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

Power and milage aren't mutually exclusive.The better the power means a more efficient engine(generally).It's using that power(heavy right foot) that makes the milage drop.The 5.3 may not do any better than the 6.0 as far as milage when driven the sams.The 6 cyl in these trucks seldom gets much if any better milage than the 350 and even some BB.The EFI engines will have better driveability and should do better on the hiway than a carbed engine,but the 6.0 may have better milage heavily loaded or towing than the 5.3.There are just a lot of variables,the biggest being how you drive.

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

[QUOTE=CC69Rat;5280451]Where are you finding these cheap (low priced) LS motors? Everything I find is $3k range and it has a boatload of miles on it. Maybe I'm just not looking in the right place.

x2 on that even on the 5.3 around here anyway

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

Can you do mine?
J/K
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Re: Whats your impression of a 5.3L LS motor in these trucks?
 

I totally agree with what you are saying. It is ALL about how you drive! haha

lata
CHRIS

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

I'm still not convinced on the "new" motors either i just don't see it my carb. vehicles as just as driveable as my fuel injection truck to me and i just can't get past the horrible looks of the newer motors vs. the old ones. One big deal for me is all the extra stuff that is with the new ones all the wiring etc. and harder and more $$$$ to fix. just my op.

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

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

A 327 you say? :) If only I had the money. I use to work at a GM dealership and I loved the 5.3's. I would always make the tires squeal when I took them to get gas.:metal: I wouldn't mind putting one in my '63, it's just the whole computer/wiring thing that would make me hesistant.

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

My son has a 2011 Silverado with the 6.2 and six speed auto, it's just an awsesome truck. He gets 20 mpg if he stays at 65 mph. It would be hard to imagine the old style 350's knocking out mileage like that in such a heavy 4x4! Plus it will run the 1/4 in 14.6 !

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

I love the 5.3 in my 2000 Z71 ex cab 4x4. I average 14mpg with it and it will easily hit 18mpg on the highway.

I put a 700r behind a rebuilt 350 in my 67 C10. I average around 12mpg and if I keep my foot out of it, I've hit 16mpg on the highway. By the time I blew money on the rebuilt engine and 700r I could have easily had an lsx/4l60 for probably less than what I spent.

I would love to put a 5.3 in my 67, but I don't want to "spend money again" on the same thing.

Also, don't forget, YES these trucks do weigh A LOT LESS than the new trucks the ls engines are in, however, the 67-72 trucks have aerodynamics like a brick! Believe it or not, GM actually spent a lot of time and money making the GMT800s and 900s as aerodynamic as possible.

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

I'm really torn with this type of conversion.Not against it,see the value in it yet not crazy about doing it either. What I like about these trucks is the way they were built. They are modern enough for daily driving even today,only gas costs have gotten crazy. You can fix them yourself with no special tools vs paying $75-100 an hour for a "tech". It's great to have more power than you'll ever need and still get great mileage,but I like knowing I can go anywhere I want in my 40 year old truck and no matter what happens I can fix it enough to get back home. I guess I'd like to have one of each...an old school reliable truck that is a s simple as it gets and a high-tech modern computerized old truck that I hope I never have issues with.

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

Yup yup 327 I say. Old school that is. My truck is power nothing and doing this swap would also fix most of those issues as well and add A/C while I am at it.

I was hard headed for a long time just saying I wanted a "simple" carb'd motor and all that and I totally understand that. But I am really leaning towards the newer small blocks because of that great driveability and power potential out of a basically stock engine. My basic plan was (before considering the 5.3L again) was to get a LQ4 or LQ9 6.0L, swap in a cam (for some good sounds and power), add some Camaro LS1 headers (cheap) , add a CAI and go from there. Cant argue with 400+ hp from just a cam swap and tune. I dont have to deal with flat tappets killing my cam because the oils these days dont have the zinc like they need. I mean it goes on and on the reasons for me IMO.

Either way you cannot go wrong. New or old the SBC is the best engine ever made. You cannot argue with torque! Something ford guys would never know about! LOL :D

lata
CHRIS

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

Well said Special-K .. Not suprised brother :D

Maybe I'm just a little afraid of them too cause if it breaks, I just don't know as much about the new ones as I do the old ones. I don't want to get stuck in some sort of Error Code / Fault Code etc. I don't know how to fix. With the old stuff, a Phillips / Flat, and a 9/16 and you can at least get home.

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

I love those lsx based engines. good mileage and great power!!

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

The "Fixability" (is that even a word? LOL) of the newer Fuel Injected and computer controlled engines seem to intimidate a lot of people. With a laptop, the right cable, and the right software package, diagnosing an issue with a newer drivetrain is actually a lot easier a vast majority of the time.

Not to mention the ability to tune the engine with the press of a button or a mouse click.

The newer engines are literally designed to go 100K without any service what so ever, besides normal maintenance. If GM wasn’t confident in these engines, they wouldn’t offer the powertrain warranties they currently offer.

Many of the “problems” encountered with the LSx engines are created by owners who do modifications.

I had a 4th F-Body with a LS1 / T56 combo. That car had close to 100K when I got it. I drove it hard. It was bone stock, no mods. When I got rid of it, the mileage was closing in on 140K. The guy who bought it planned on yanking the motor when it gave up the ghost, and building it up. He’s still driving it. In fact last I heard he was planning on pulling it because the clutch was ready to be replaced. The engine itself was still going strong. He did mention he hoped to see 200K on it before yanking it.

Keep in mind that this car saw the drag strip on average probably once a month. And it wasn’t babied.

I’m currently on the lookout for a 4.8/5.3 combo for the kid’s ’65 C10 we’re starting on. If the price is right, I’ll pull the trigger. In my area it’s actually cheaper in the long run to buy a wrecked or otherwise damaged vehicle and pull the drivetrain and part out the rest. Reason being that people have caught on that these engines are popular for swap material. A guy I used to work with buys the newer style trucks and SUVs with the LSx drivetrain and parts them out. Around here the it’s not unheard of to get an easy $3K for a complete 5.3 with tranny and wiring harness. The other issue is that a lot of potential swappers bought engines, not realizing they needed the wiring harness, PCM and the tranny.

I’ve seen guys try to piece together the drivetrain because they got a “Good Deal” on the engine, only to end up spending as much or more than they would have if they bought the entire drivetrain, ready to go.
As far as cost comparison with building an older style small block Chevrolet, the divide is closing.

Like someone else mentioned, if you’ve got a good running engine now, then swapping in a LSx drivetrain, unless you get a GREAT deal, is not the most sensible choice from an economic perspective.

If you have a truck without an engine, or an engine that needs a total rebuild, the cost could be close to a wash. It all depends on what you want out of the engine in your truck.

Buying a good running very mild 350, cleaning it up and throwing in your truck is a far cry from a properly setup LSx engine.

Building a good performing, reliable old style small block Chevy is not a far reach (in cost) from a stock 5.3. And that’s doing all the wrench work yourself.

That being said, most of us who work on and drive older vehicles, we know that it doesn’t make the best economic sense to begin with. If it was all about saving $$$, we’d all drive a 30mpg + compact car.

Now of course many times we try to use other “arguments” to convince ourselves (or our significant others LOL) that “Swapping in a 5.3 and OD for the 350 / 3 speed will save money.” Sure it will save money on gas, but what about initial investment? The other things needed to do the swap? The wiring work, the tuning etc?

I also see people “justifying” their swap by talking about how much more “driveability” the new engines have.

“Just crank the key and go.”
“No need to adjust the carb etc.”

I don’t know what conditions some of you are driving in, but I’ve had both modern EFI engines, I’ve retrofitted EFI (mainly TPI) engines into project cars, and I’ve also daily driven carb’d engines.

I drove a 408 small block with a single plan intake and a carb setup EVERYDAY, rain or shine. Averaged 20k+ the two years I drove it. Did it get wonderful gas mileage? Of course not, it wasn’t designed or built of that. But with a moderate rear gear ration and a 5 speed tranny, it didn’t do as bad as you might think. I drove that car when the temp was 10 degrees and when it was 100 degrees. I don’t ever remember having to do a lot of “tuning” for weather conditions. It’s not like I was driving in massively different altitudes every week.

In fact I put right at 50K on that engine, and the only thing I remember doing to it was changing the HEI cap and rotor, because I had used a “freebie” replacement when I dropped the engine in, and it crapped out on me.

In the end it will always be the owner’s choice, as it should be.

If you plan on swapping a LSx engine into your truck, and you have a decent running engine now, if your primary reason for swapping is saving money, you’ll likely end up disappointed.

It’s the same boat as people who traded in paid off Surburbans and Tahoes when gas prices first jumped after Katrina. They traded 12-14mpg and no car payment for AT MOST a mpg twice as good, plus the car payment. It would take YEARS for many of these people to ever realize any true savings. But I’m sure they felt better when they weren’t dropping $100 at the gas pump every week.

I guess this long-winded post is simply meant say…

“Do what your wallet and your ability allows. As long as YOU like it, who cares what anyone else thinks.”

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

Great post! I enjoyed reading it! haha Long winded or not! :D

lata
CHRIS

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

i agree...... but for slightly different reasons...

I work at a mechanics shop and we work on late model stuff. Most of it is really not too bad once you get to know it........

BUT....

There is just alot of fun in driving around with old school technology..... being able to fix almost everything on the truck with two screwdrivers, a set of wrenches, baling wire and duct tape if you have to. sure the mileage isn't that great.... but so what...

I used to be all for putting modern technology in a classic vehicle.... but not so much any more.... there is something to be said for the old school stuff.... fun you just can't get with modern stuff...

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

I'm looking hard at doing this very swap. I am pulling the 496 BBC from my truck as 6 mpg doesnt seem all that fun (not to mention way too much power than I need unless I get back into track weekends). Comparing the costs of buying a Gen II roller crate 350 to the swap and it seems to be more or less of a wash. Of course, prices will go up quickly if I get stuck and have to let someone else finish it for me... If I go with the 350 crate, I can be back on the road in 2 weekends max.

Its a lot to consider, but I am a big believer in future-proofing and gas is only going up. If I can keep costs close to the same, the 5.3 is a no brainer. There are lots of good builds on this site for tips, but it is very daunting to dive into.... Eh. So much to consider.

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

Honestly its going to cost 50% more than you think;):)

New motor mounts,tranny mounts

drive shaft

F-Body oil pan

throttle cable/throttle by wire set up

New headers and exhaust

New fuel tank,lines and pump,return line

wire harness or someone with alot of knowledge about the factory harness that can weed through the spiders nest.

PCM

Tuning software or a custom tune

If you are a fabricator/mechanic by trade/hobby I could see this swap happening for less than 4K if you get a good price on the motor/trans and really shop the parts and do all the fab/installl.

If your paying a shop you could easily end up in the 7-10K range.(thats alot of gas;))

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

Why do this swap unless you’re going for something like the stock z06 vette LS7 motors that are 500+ hp stock? The 5.3 is an ok motor but for the money/time/trouble I don't see what the point is. Get a set of good flowing heads, that is all the LS motors have going for them except maybe they are a little lighter.

My vote is no on the LS swaps and I did research it extensively when I swapped my last truck from I6 to 350.

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

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?

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

I think alot of people are just intimidated by the computer, yet everyone commenting here is on one!
Seriously though, you were not born knowing how to set the timing on a 350, you learned it. And before someone mentions the special equipment needed, you weren't born with a timing light, dwell meter or a vacuum gauge. Sure the newer stuff costs a little more, but that's lilife, things go up.
Im sure if you all head over to the HAMB, you will find guys that say the flathead Ford is the greatest engine of all time and thatyyour SBC is too modern. Probably what people said about the SBCin these trucks when they were new, "these new trucks with their vacuum advance, automatic transmissions and power steering brakes and air conditioning, how are we supposed to work on them?!"
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Re: Whats your impression of a 5.3L LS motor in these trucks?
 

Hahha so very true.... Its amazing how that happens!.

lata
CHRIS

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

To me the computer has nothing to do with it. It all comes down to a lot of work & money for nothing gained.

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

Nothing gained? I wouldn't say that so much.

lata
CHRIS

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

The correct answer to the question though, is, there is no correct answer. It boils down to what YOU like. If we were all the same the world would be a very boring place.

If we woke up tomorrow, and suddenly it was 1972, the purists would be the guys restoring Model A's, while us LS swap guys would be the ones hot ridding them. Its really to each his own. ;)
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