Whats your impression of a 5.3L LS motor in these trucks?

[CC69Rat]

Just some numbers to consider:

Daily Driver (using my own)
@ 450miles per week 15mpg I burn 30 gallons. At $5 gl = $150 per week
Same numbers - 25mpg I burn 18 Gallons = $90 week.

I don't drive my trucks every day. Most of us don't if I had to guess.

$240 mo - it would take me about two years to offset the cost of gas @$5000 for my LS swap (done how I would do it). That's a daily driver. No way I drive either one of my trucks 450 miles a week. .. so the time for ROI would be at least 4 years.

$240/mo would pay a monthly payment on a Hyundai, and I get 30+ mpg.

I personally (no disrespect) think the LS swaps are just a craze. The coolness factor, and all the cool kids are doing it. If the 'old school' stuff was going away it would have already gone. Just my opinion. Watch Pass time? How many LS motors do you see. How many big blocks? You want Raw power? How many Top Fuel LS motors have you seen? The Big Blocks still have everything they always had IMO. I'm not about to crush my Big Block just so I can have a 5.3L in my truck. .. just sayin. And it looks like Ole Greenie is still pretty proud of his LS6 @$7500. I would be too.

There's still something to be said about a cleanly detailed carbed motor. I like the LS stuff too, but I just can't justify the cost of the swap or putting an engine in my truck that I haven't gone through myself. I just know more about the old stuff. .. cause I'm old I guess. I have a wife, a mortgage, and a 50hr week job.. My old 350 3OTT will do for now. I can't return $5,000 in the value added to the truck.

If it were a daily I might feel differently but I may put 100 miles a week on my GMC. the rest of the time I ride with my wife, to / from work .. in our Honda CRV.

I'm good with mine as they are for now. $10 a gallon, .. what can we do about it? Crush all the old stuff and sell it for scrap? Why not just buy a new Silverado? Where will they be 43yrs from now? Just my take on it.

[468BIGBLOCK]

Originally Posted by OldCreek

These swaps always seem to "nickle and dime" me to death, though.

Remember this, we all talk about getting a LSx motor and tranny for a "cheap" price. But in reality, we're usually taking a gamble. How do we really know if the engine needs new gaskets or if the tranny needs a rebuild, etc?

my daily driver is a 01 suburban with 260K MILES ON IT. it does not need anything replaced on it it dont leak any where. i dont why you would think that a lower mileage engine purchased from a reputable salvage yard or dealer would have any problems.

[HuggerCST]

Originally Posted by CC69Rat

I personally (no disrespect) think the LS swaps are just a craze. The coolness factor, and all the cool kids are doing it.

I used to think the same way, especially after the LT engines came and went. Going with the latest fad would only leave your build looking "dated" after a few years, but the LS has been around long enough that they are very common now, and seem to be slowly taking the place of the sbc because of it. Only time will tell. Though still plentiful, the sbc and bbc engines are slowly disappearing from the salvage yards. It's nice to be able to buy & install a 100,000 mile engine without rebuilding it, have good power, fuel mileage, and be able to put another 100,000 on it without major repairs. As much as I like old school, most LS engines are outlasting the vehicles these days. It's rare for a carburated engine to go 200,000 miles without internal problems. It's all about what you like though, and what you want to do with it, how much you drive it, etc. Like said, you can buy a lot of gas for what it normally costs to swap.

[Cole Trickle]

Originally Posted by CC69Rat

Just some numbers to consider:

Daily Driver (using my own)
@ 450miles per week 15mpg I burn 30 gallons. At $5 gl = $150 per week
Same numbers - 25mpg I burn 18 Gallons = $90 week.

I don't drive my trucks every day. Most of us don't if I had to guess.

$240 mo - it would take me about two years to offset the cost of gas @$5000 for my LS swap (done how I would do it). That's a daily driver. No way I drive either one of my trucks 450 miles a week. .. so the time for ROI would be at least 4 years.

$240/mo would pay a monthly payment on a Hyundai, and I get 30+ mpg.

I personally (no disrespect) think the LS swaps are just a craze. The coolness factor, and all the cool kids are doing it. If the 'old school' stuff was going away it would have already gone. Just my opinion. Watch Pass time? How many LS motors do you see. How many big blocks? You want Raw power? How many Top Fuel LS motors have you seen? The Big Blocks still have everything they always had IMO. I'm not about to crush my Big Block just so I can have a 5.3L in my truck. .. just sayin. And it looks like Ole Greenie is still pretty proud of his LS6 @$7500. I would be too.

There's still something to be said about a cleanly detailed carbed motor. I like the LS stuff too, but I just can't justify the cost of the swap or putting an engine in my truck that I haven't gone through myself. I just know more about the old stuff. .. cause I'm old I guess. I have a wife, a mortgage, and a 50hr week job.. My old 350 3OTT will do for now. I can't return $5,000 in the value added to the truck.

If it were a daily I might feel differently but I may put 100 miles a week on my GMC. the rest of the time I ride with my wife, to / from work .. in our Honda CRV.

I'm good with mine as they are for now. $10 a gallon, .. what can we do about it? Crush all the old stuff and sell it for scrap? Why not just buy a new Silverado? Where will they be 43yrs from now? Just my take on it.

I wouldn't say there a craze.....

There the evolution of the SBC. If you think part for part a standard off the shelf sbc will compete with a newer improved more efficent lsx your kidding your self. There are plenty of 5.3 and 6.0 motors out there on the cheap so that what will find its way into our engine bays.

I love the simplicity of my carbed sbc in amy old pick up truck. On the flip side I wouldn't want one in a pro touring big dollar build. I would do a blown ls2/3 or perhaps a LS9 if the budget allowed it in a heart beat.

If your not daily driving it (my sbc with the 4 speed and 3:08 gears actually pulls good mpg) and you have a good running sbc why spend 3-5K for a swap when you can easily get 300 to the wheels with heads and cam for less than $2000.

When the world comes to an end I don't want electronics on my machines...lol

[CC69Rat]

Yall pickin on me? (kidding)

That's why I like this forum. You can express your opinion and still show mutual respect without someone getting their feelings hurt. just discussion..

I have a $5,000 titanium frame road bicycle too and I can justify that all day long ! It's all a matter of opinion so please take what I'm saying as that. Just speaking for myself here, I mean nothing I say as offensive. .. just for the record.

I respect the LS stuff too. I have owned many of them. I am 38yrs old, I have owned 37 cars in my life. I get around a litle bit. Bottom line, I'm not afraid of computers (Im an IT security admin, Telecom guy) I just can't justify the swap for my toys.. and the wife won't let me spend the money.

I have to defend my SBC till the stop selling parts for them. Kitchen remodling, new roof, and International adoption is coming up soon. I gotta make my 408ci BBC, and 350 original matching numbers 0010 block work for now. She doesn't HAVE to give me those,.. but she's cool enough about it to let me play. I have two C10s and appreciate them all. Straight 6, or LS9 it's all the same to me.

[BlazinC5]

When I was kid, looking into ideas for a career, My father and I had quite a few discussions. One of them was about beeing an auto mechanic. His personal take on it was of course the old school thought of things. Saying things like, there are lots of backyard mechanics out there to compete with and vehicles are getting harder to work on every year. And why they need a computer to run makes no sence when a carb works just fine. After being talked into being a machinist instead and around 20 yrs later, Was he rite? Well, yes and no.
Pesonally, I find the new stuff harder to get my dang hands into when working in the tighter spaces, not so much about figuring out what is wrong with it, like my dad was thinking.. An OBD2 code reader isn't all that expencive, especialy one from walmart. And they can tell you what is wrong down to what plug was misfiring. Sure seems to help eliminate the guesswork. My first EFI engine was a 87 camaro with a TPI 305. I had no idea how it worked I just wanted the car. But I went throught the whole engine bay, fixing all the typical white trash wire rats nests, disconnects, and faulty parts, learning from books on how and why it works the way it does. I Also learned how simple it really is. Since then EFI to me is the way to go.
If you get rite down to it, EFI is just a monitoring system that says "ok, add fuel, spark the plugs did I get it right? oops, adjust and try it again, is it rite now,, If it ain't that idiot light is going to come on cuz something is jacked the F up in here buddy." Compaired to carbs, similar results, just a different way of doing it.
I haven't decided on exactly what engine I will be putting into my 71, But I know it will be LS. I have read every post in this thread and I also notice people complaining about the added wires, electronic gas pedal, hiding the computer/ ect. Stuff that don't look very good in most peoples eyes. And we'll just leave the plastic cover issue alone. lol.. But, I say get creative to hide it. nothing says a wire has to be exposed. So tuck it away, loom it, make a cover of your own for it. We who build these trucks are just redesigning what is already out there, rite? so mod it up if your so concerned. My truck does need a whole new engine reguardless and the way I would want an old school 350, it would cost close to the same as putting in a salvage yard 5.3. So I feel upgrading to the newer stuff would be beneficial in some respect of stock fuel ecconomy/H.P. even though the work and effort to do so is alot more. But hey,,, It's a hobby to me, half the fun is trying to figure things out and make it truly mine...
BTW, a few years before my dad had a stroke and could no longer drive or work on stuff, he did embrace the new tech stuff pretty well, Course that took some late nights of BSin and many a bottles too convincing.

[19seventeeCustom]

lsx a craze??? I don't think so. the ls stuff were
using today is the new sbc. it's simple evolution.
just wait until gen 4 stuff becomes more affordable,
500hp with cam only setups, how can anybody that
considers themselves a hot rodder be against that????

lsx- makin sbc/bbc look bad since '97 lmao
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[OldCreek]

Originally Posted by 468BIGBLOCK

my daily driver is a 01 suburban with 260K MILES ON IT. it does not need anything replaced on it it dont leak any where. i dont why you would think that a lower mileage engine purchased from a reputable salvage yard or dealer would have any problems.

This is not a knock on the LSx. In fact, I've bought used Lsx engines from the yard and off of craigslist. However, do you not see an inherent risk from buying a product that you can not first see/hear run? At best, you may get a trade in or your money back but that can't refund the time you wasted getting and installing said item.

It is certainly a risk...one that I'll probably keep making in the future. Is the cost worth the risk...evidently.


On another note, I sure enjoy being in my old trucks than my current daily driver. That's why I'm building one to get to that D.D. stage. Hopefully, I can get the mpg up there...but I will accept something close. I can't think of a Hyundai that would make me smile everytime I got into it....

[BrutonLS1]

Originally Posted by 19seventeeCustom

lsx a craze??? I don't think so. the ls stuff were
using today is the new sbc. it's simple evolution.
just wait until gen 4 stuff becomes more affordable,
500hp with cam only setups, how can anybody that
considers themselves a hot rodder be against that????

lsx- makin sbc/bbc look bad since '97 lmao
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Well said!! I rebuilt an Ls1 but got in a bind and had to sell it...sad sad day.
but I just swapped my 327/th400 with a 5.3/700r4
The 5.3 is bored to a 5.7 with LS1 crank, cam, pistons,etc. I didn't keep the fuel injection though, I'm going with a 650cfm carb. I put the exhaust on it today, wiring it tomorrow. Here's a pic of the engine before I put it in the truck, When I finish it this next week I'll definitely post up some pics and let y'all know the gas milage, hwy rpm's, etc.

[eagleuh1]

I have a 68 C20 that I rebuilt the stock 327 in it. Just wasn't happy with the milage and performance. I also had a 2005 5.3 in my S10Blazer that I kept cracking the frame at the front suspension mounts. I've worked with both types of engines since I was a teenager. Loved them both. But since I put this 5.3 in my C20, have been very happy with its performance and OK with the milage. Still learning how to use HPTuners to tune myself, hopefully get better milage out of it. Personally I wouldn't go back just beause these engines are so easy to work on and troubleshoot. Especiallly if you have HP Tuners scanner. I've driven mine all over the country towing a travel trailer( 68 28' airstream) and have never had a problem with the engine or tranny. Tows with plenty of power to spare, has never overheated. And runs fine in traffic in the city. I spent more on the 5.3, but probably have saved it back on gas. Just my view. Like the 5.3 better. Good luck however you go though. jim

[eagleuh1]

Oh, they didn't have the 5.3 when I was a teenager, but I worked on Ford 289's and Chevy SBC since a teenager.

[trac209]

[quote=BB72CHEVKT;5280035]

Originally Posted by CC69Rat

I have a 350 / 3OTT pretty stock with a 1406 Edelbrock, aluminum intake, ramhorns and Flowmaster / 2.25 exhaust and it gets at least 20-22 on the freeway.

I have never owned a 350 that got close to those numbers.

Me either.
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[ubtripn]

I am planning on getting the 290 horse GM crate engine when my 350 goes. With the right Rochester and HEI I think I can get it to a point where I don't have to tune it too often. I like the new engines but I got my 68 because of the older technology. I wanted cheap replacement parts as well.

[69GWC]

I have a 06 with a 5.3 and have had many many trucks and the 5.3 is a great motor gets ok mileage but I would rather have a 350 that made good power down low then have to scream the piss out of this 5.3 to get to the power, I feel the power band on the 5.3 is way to high for a truck and even more so if your pulling stuff.
Its funny I shift my 69 around 4000rpms and my 5.3 is just start to find some power at that point..lol

I had a 94 350/700r4 with 3.42s and it did better on fuel and pulled much better then tthis 5.3 with the same gears.
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[nlped]

Well, I'm going with a 2002 5.3/4L60e swap in my '70 model. The current drivetrain averages about 10-13 mpg's and is a cold natured critter...I love the idea of hopping in, turning the key, and instant response. I've done quite a few FI swaps in other vehicles...never have done this one, but I'll get it all figured out with all the help available on this site.

BTW...the LSX swap I got for $1100 came out of an '02 Suburban with 83k miles on it. Came with motor/trans, complete wiring harness (including the underhood fuse box, battery cables, headlight harness, cruise control module, etc.), the entire system from the motor to the gas tank (gas tank not included) and all the accessories. Heck of a starting point if I do say so myself

[68Stepbed]

I recently finished my LS1 swap in my 68. As for money, I'm way ahead than if I had rebuilt the SBC. Just a simple rebuild with a little massaging to get it with some grunt was going to run me $3000+. I could have also reused my TH350, but how long would it have lasted behind an engine with more power? For $3K, I would have had a 355 making about 250rwhp.

Currently, with the LS1, 700R4, and everything, I'm at around $4K. I still have to build the rearend with 4.11's, so figure another $600-800. My stock LS1 with a cam and valvetrain upgrade is making close to 400 rwhp.

I would have to spend close to $5K just on the engine to get those kind of rwhp numbers from a SBC.

Also, with my old 350/TH350 combo, the best I ever got was 16mpg with 3.73 gears, and 18mpg with 3.07 gears. I haven't currently checked mileage since the rear gears aren't correct, and my speedo isn't hooked up yet, but based on my trip to Chattanooga a few weeks ago, I'm close to the same mpg(3/4 tank each way).

I'm also running a carbed setup, so my numbers may be a tad lower than an EFI setup will make. When I finally get everything tuned out and the correct gearing, I'll start crunching some mpg numbers to see what I'm actually getting.

[69GWC]

$3000 to rebuild a sbc and only make 250hp..? You can buy a crate motor making over 350hp for that.
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[Critter]

I have a huge bias in this conversation, but because my name on here is blue and not gold (yet) I will keep my comments to a minimum. I will say that up until a couple years ago, you wouldn't catch me with anything other than a carb under my hood but times they are 'achangin'. I made myself jump into the LS world and I am loving it so far. You can't beat the price vs efficiency vs power aspect of them. To those that weren't impressed with a 5.3 in their ride I can almost promise it was a product of improper tuning. Maybe improper isn't the correct word, I should say, tuning that wasn't matched up to the current vehicle the motor is sitting in.

[el_diablo]

If you guys are swapping in 5.3/4l60s and staying fuel injected, make sure whoever tunes it adjusts the torque management/throttle body response. Stock tune, they are absolute dogs because of that.

Food for thought on tuning- I had an 06 regular cab Chevy with a supercharged 5.3/4l60 and got 21mpg on the power tour in '08.

The built LS7 in my C6Z- I got 30mpg the day I bought it and drove it from Kansas to OKC.

I made multiple trips from OK to California and back with my old 2001 Z28 and always got 25-30mpg depending on how I drove it.

[68Stepbed]

Originally Posted by 69GWC

$3000 to rebuild a sbc and only make 250hp..? You can buy a crate motor making over 350hp for that.
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Keep in mind I'm talking rear wheel horsepower(rwhp). All crate motors are dynoed using the "gross" method at the flywheel. which means how much power it makes with no accessories. The "net" ratings are what are now used, which determines power with all the accessories installed and working. Then there's rwhp numbers, which always seem way lower than the "gross" ratings due to the power lost in the drivetrain.

For example, the old engine in my truck was a "260 hp" GM 350. If you look it up, it will tell you they got that number using a 4-bbl carb and intake with 1 5/8" headers and the water pump installed, which usually means it's only connected to the crank pulley. It also doesn't specify which carb and intake is used. That engine will typically only make 190 hp with all the accessories on it, then only makes about 135-150 rwhp depending on drivetrain variables.

That means a 350 hp crate engine will only make around 225-240 rwhp.

[CC69Rat]

LSX - Makin SBC/BBC look bad since 97.. lmao.

Check my previous post. I have owned an LS motor before, Trans Am and it would run. I give credit where credit is due, but I also recall a 67 Camaro showing me some tail lights one night. LSx is not unbeatable fellers. I didn't poke at anyone, I'm just trying to understand the hype. If they're that powerful, I'll look harder at the swap. Again this is not my daily driver .. so it will take me a LONG time to re-coup the LS swap expense. Do I pull my perfectly good running 350 out of my cruiser to have a good running LS in it, just so I can say I have one? Yall must have more money than I do.

['72customdeluxe]

You guys already have your minds made up, but oh well. My '05 lm7 (iron block 5.3) long bed that probably weighs more than stock ran a 14.49 with a breathtakingly slow 60'. 97 mph trap with headers and a tune. Now my pinion angle is about -3* instead of +5*, better tires, better tune, and have traction springs. Hoping for some decent improvement with those changes running it at sea level in cooler air. Gets around 21 on the interstate with 3.73 gears and 30" tires.

[68Stepbed]

Originally Posted by CC69Rat

I didn't poke at anyone, I'm just trying to understand the hype. If they're that powerful, I'll look harder at the swap.

It's not that they make THAT much more power, it's the WAY they make it. The valve angle allows for a different flow path of air/fuel for better atomization at higher rpms when the air gets turbulent, which makes for more power and better efficiency. This along with the lighter weight rotating assemblies, will allow for power levels to climb well into 6500-7000rpm ranges. Any old small block is pretty much spent by 5500 unless you start throwing alot of go-fast goodies in it. Keep in mind these are the same "type" of go-fast goodies that LSx motors come with in stock form.

The one advantage old sbc/bbc engines have is low end grunt. The 23 deg valve angle allows for better fuel atomization at low rpms, but is limted at higher rpms, which is still much better for a towing application.

Originally Posted by CC69Rat

Do I pull my perfectly good running 350 out of my cruiser to have a good running LS in it, just so I can say I have one?

To that question, I say no. As you stated before, it would a long time to recoup the costs(as far as fuel mileage). If what you have is efficient and works great, and you don't need the extra power, why would you?

Now, if your engine trans combo is getting tired and weak, and it needs replaced anyway, then the answer would be a big YES!! I say that because you can pick up good, used engine/trans combos for what a machine shop will charge you just in labor to build an engine.

Also, if you have a good running setup, but it's not enough, and you want more, then that's another reason to say yes. The reason is it's very hard to make a sbc make good power and still get good efficiency(I'm not saying it can't be done, I'm just stating that it's not an easy task.). The LSx engines are a great combo of power/efficiency.


All that said, the typical costs of swaps that I have seen run anywhere between $3500-$5000+ depending on which engine/trans you get and how many "upgrades" you put into it. As I stated before, it'll cost $3000+ to get a sbc built to make some decent power, then you have accessory drive system, carb, dist, etc. etc. on top of all that. We haven't even discussed getting a trans built yet.

When I did the L6 to V8 swap in 2000, I went with the stock $1500 GM crate engine, but after I bought everything else, and had the trans built, I was over $4000 for the total and still hadn't touched the rearend.

[truckster]

I've never owned an LS, but I've got a 5.7 vortec motor in a 2001 van. I've not been impressed with it, either for power or reliability. In fact, my 97 Ford 5.4 had more power and better mileage in the same size vehicle.

Having said that, my DD Blazer has a stock 350 except for the HEI. I put a Quadrajet back on it (replacing an Edelbrock 1405) and I pump the throttle once and turn the key and it fires right up, whether it's 10 degrees or 110 degrees. I've never had any issues with overheating in traffic. I might be able to get better mileage with injection, but I doubt it would be much more; overdrive would probably make more of a difference.

It's your truck; do what you want with it. But I don't think any motor is a magic bullet to making a brick fly through the air and give incredible mileage.

[CC69Rat]

Matt- well said man. Its tough to express tone on here. Just know I wasnt trying to be a DB. I just want to know the'why' part. What you said makes sense. The others too.. just trying to learn.
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