383 or 5.3?????????
 

OK, I'm trying to make a decision here, my vortec-headed 350 lost oil pressure and needs a rebuild. the motor and heads had less than 7000 miles on them

I'm considering 2 options:

keep the vortecs and build a 383 short block with good rods and/or forged pistons, and a bigger cam.--aprox 400 hp

or

I think I can do a 5.3 swap for about the same price as the 383 short block i'm planning if i sell the heads, manifold and distibuter.--aprox 300 hp

the reason I'm considering the 5.3 swap is that its a daily driver and the Fuel Injection would be really nice. Eventually I'd mod the 5.3 to get more power. but for right now it would be stock.

opinions please.

Re: 383 or 5.3?????????
 

5.3l

Re: 383 or 5.3?????????
 

383

Re: 383 or 5.3?????????
 

I would do a 5.3, but then again I am a computer geek so that would be fun to me.

Re: 383 or 5.3?????????
 

cant go wrong with a 5.3!

Re: 383 or 5.3?????????
 

I've never really cared for high HP motors in trucks, especially drivers. I can definitely appreciate a fast truck, but they're not really for me. Definitely 5.3, especially since you already have the 700R. Can you buy a harness for a 5.3 w/ 700R or does it have to be a 4l60E?

Re: 383 or 5.3?????????
 

I have a 383 in my 69, while it is fun (especially in today's rain hehe), the money I've sunk in it over the course of 2 rebuilds in 3 years coulda gone a lot further towards something better. Could have a nice LS crate at this point, an LS based anything would be much more worth that amount of coin then a 383 in my opinion. Granted my 383 had issues from day one that has brought me to this opinion but I had to have a 383. Gotta love hindsight.

Re: 383 or 5.3?????????
 

5.3s are great engines, good milage and decent horsepower. but if your in a big rush to get the truck runnin again the 383 is basicly a drop in thing. but if you want the horsepower with decent milage spend a few hundred bucks more for a 6.0L.

Re: 383 or 5.3?????????
 

the 700r4 I have is non-electronic, to make it work with the 5.3 I'd have to use a DBC (Drive By Cable) throttle and hook a TV cable to it. I assume that I'd use a harness and a computer simular to a manual transmission

Re: 383 or 5.3?????????
 

here is what concerns me about the 5.3

My old vortec headed 350 with 260High Energy cam
http://i714.photobucket.com/albums/w...sc1e/360he.jpg

the vortec headed 383 with a 268 Extreme energy cam
http://i714.photobucket.com/albums/w...sc1e/383XE.jpg

the stock 5.3
http://i714.photobucket.com/albums/w...musc1e/LM7.jpg

this is desktop dyno so I expect the HP/TQ figures are a little exaderated but look at the torque of the 350 and the 383 compared to the 5.3, I know the fuel injection will make up for some of it, but I'm still a little worried that this will be like driving a weak 305,
it wouldn't be so bad if it werent' for the 3.08 gears, which, when I get the money, I'm changing out the 3.73's

Re: 383 or 5.3?????????
 

My 2000 5.3L Z71 is drive by cable. Not sure which year GM went to drive by wire. I think '03.

Re: 383 or 5.3?????????
 

i would save some extra and do a 6.0

Re: 383 or 5.3?????????
 

5.3L all the way.

My '05 silverado crew cab with 3.42 gears would run circles around my old 97 tahoe with vortec 350 and 3.73 gears

The LSx engines have so much potential. Just a cam swap will get you a long ways.

Re: 383 or 5.3?????????
 

383. I love the way my truck drives. That cam you picked is just perfect. Lots of TORQUE!!!!!! The VORTEC heads make good power and you already have most of the STUFF you need.

Re: 383 or 5.3?????????
 

5.3 gets my vote. Killer hat 3.08's and it was awesome...had plenty of power from take off and out on the hi-way....it was a perfect combo for a daily driver...you'll definit. be surprised..

Re: 383 or 5.3?????????
 

For a weekend vehicle I would build the a serious power house but for a daily driver I would just put a nice stock pretty motor. I do not know anything about the new technology with computers and what not so I will have to vote 383 mainly because lack of knowledge..

Re: 383 or 5.3?????????
 

The 5.3 will definately have enough hp. If your engine is drive by wire and you want to change it to cable you can just swap out your throttle body or change the peddle to make it a dbw. The only concern you want to check into is the 700r4 b/c I had one attached to my 5.3 and never could get it to shift right. The tranny man said it never would. There isn't a spot for the dt cable and I fabricated one but it never shifted like a 4l60. After I put in the 4l60 mine shifts like a new truck and and gets over 20mpg. The 5.3 is definately the way to go.

Re: 383 or 5.3?????????
 

My vote is with the 383.... high torque and low rpms.

Re: 383 or 5.3?????????
 

I'd go with a 383 with fuel injection.My .02:chevy:

Re: 383 or 5.3?????????
 

Ooh, theres the best of both. I'd love to put fi on my 383 but can't afford it. The instant throttle response with all that low torque would be fun. Definitely something else to consider op.

Re: 383 or 5.3?????????
 

If I had the means to swap out my L6 would have to go with the 5.3L just think it would be a great setup.

Re: 383 or 5.3?????????
 

did you really say the 5.3's 300 ftlbs of tq at 2000 rpm would be like driving a weak 305?

5.3 gets my vote, cant wait to get mine done. its hard to beat 300 hp and 20 mpg in a truck. plus mods are awesome over 400hp with headers cam and tune alone.

Re: 383 or 5.3?????????
 

alright, I'm leaning toward the 5.3.

a 6.0 would be really nice, but does anyone know where i can get one for less than $1000 shipped???????????????????????

I'm really ready to get back in my truck. :chevy::chevy::chevy:

Re: 383 or 5.3?????????
 

Might as well go with a ramjet 502 :metal: -- I'd love to, but I'm a little broke right now

Re: 383 or 5.3?????????
 

found a 6.0 for $775 shipped, good deal???

Re: 383 or 5.3?????????
 

I agree with above statements: daily-driver = 5.3 economy

weekend-warrior = 383 high HP

I love the old-school power and feel of my 406, but I wouldn't like the gas bill as a daily driver...

Re: 383 or 5.3?????????
 

thats a realy good deal, some 5.3s are priced higher than that, does it include the tranny and computer?

Re: 383 or 5.3?????????
 

If you swap from DBW to a cable TB the harness and PCM will need to be modified for the additional sensors, IAC and TP. Just something to keep in mind. I vote for the 5.3 or 6.0. Put a cam and springs in it and call it good.

Re: 383 or 5.3?????????
 

You're talking a whole lot more work to put that 5.3 in your truck. It will end up costing you alot more than you think in the long run unless you try to cut some corners (not a good idea). And from what I read it looks like you're shopping for someone's used motor.

If your other option is to build a brand new 383 then my decision would be made. I mean, how many times do you want to start over? :lol:

I'd build the new 383, stick it in the truck. When money shows up down the road, add the fuel injection to it.

Think of it like this............

383 = Brand new engine with WAY more pull in the low range.
5.3 = Used engine ALOT more work.

Like I said, my decision would be made :metal:

Re: 383 or 5.3?????????
 

no tranny, computer, harness or accesories

Re: 383 or 5.3?????????
 

I know, but I'm worried about loosing my motor again to another cam failure, that would cost more than doing a 6.0 or 5.3 swap

Re: 383 or 5.3?????????
 

So you're nervous about putting another flat tappet cam in your engine and having it fail during break in like the last one?

I'm assuming you've considered putting a roller cam in your 383 then to cure that problem and you're thinking that the cost of that would be about the same as going to the 5.3?

Trust me, an "all roller" 383 built from the engine you're pulling out right now is not going to cost you more than the swap to the 5.3.

So, this formula still holds true............
383 = Brand new engine with WAY more pull in the low range.
5.3 = Used engine ALOT more work

Re: 383 or 5.3?????????
 

my 5.3 swap was not bad but yes it can get spendy. Mine stock ran great I did a cam swap nothing too wild and a good tune I ran consistant 13.8 at 94 in the 1/4
now with a conservative 50 shot of NOS I dropped to 13.3 at just over 100 mph with street tires and 4l60e tranny. It seems to have plenty of power.

Re: 383 or 5.3?????????
 

you can make a 5.3 as powerful as a 383, a 6.0 will make even more power aswell, it all depends on what you want to do, from what ive seen nobody as ever regreted going to the new LS swap... they are very dependable, economic fuel mileage, and make alot of power....

Re: 383 or 5.3?????????
 

do you mind me asking what size cam you put in the 5.3?

Re: 383 or 5.3?????????
 

I looked at a budget build to drop a 5.3 into a truck and the guy came back at $1500 done deal. I have an 06' swb reg cab with a 5.3 and it gets 17mpg with me beating on it and it has 325hp with headers at the crank. These are 200,000 mile engines all day long. You don't even change the spark plugs for the first 100k. Keep it under 65mph and see 20-21 mpg. I can't see the 383 comparing for a daily driver. Down the road add a magna charger and put down almost 450hp at the tires for about $4k. All day long reliability.

Re: 383 or 5.3?????????
 

383 imo.:smoke:

Re: 383 or 5.3?????????
 

Personally I'd trust a 100k mile LSx more than a brand new gen 1, but that's just me. IMO, a 5.3 or 6.0 swap, even with a cam, would be cheaper than a good 383 rebuild, and get you the same or better power.
OP: Would you be building the motor yourself, or buying a complete short/long block?

Re: 383 or 5.3?????????
 

yeah....i agree with the 383 w/ fuel injection

old school torque but with sophistication

Re: 383 or 5.3?????????
 

http://i4.photobucket.com/albums/y14...MC/truck11.jpg




This is my own personal 4x4. That's the engine I built myself. I did away with the fuel injection, I did away with the computer controlled timing, no O2 sensor, no electric fuel pump. Pretty much the same as the '76 model truck I pulled the engine out of and I can tune it in the blink of an eye for whatever I'm getting ready to do with it. It's a 4-bolt gen1 350 bored .030 over, forged pistons, a good sized hydraulic flat tappet edelbrock cam, 3 angle valve job, milled heads, dual plane intake. It has an HEI distribtuor, an edelbrock 4bbl carb and 2.5" exhaust with headers. It's not only a daily driver but I punish this truck on a regular basis. I go mudding whenever I can (you can see the mud baked onto my headers) I drag my 21' ski boat to the lake with it all summer, I haul trailer loads of material and equipment all the time at work and I just drug my '72 chevy from Rogers Arkansas to Oklahoma City on a trailer at 70mph with the A/C on and absolutely no problems. The only change I'd need to make this engine a 383 is a crank and rods. And if I find a reason to pull it out again that's exactly what I'll do with it.

The problem with asking the question of which engine to use is that you get everyone's personal opinions stated like they were facts.

I'll give you some facts. A 383 is a 6.3L engine with the stroke of a 400 small block. Power comes from displacement and torque comes from the stroke of the crankshaft. The longer the stroke, the more torque you can make. Anyone that tells you a 5.3L will make as much torque as a 6.3L built the same has no clue what they are talking about. Those aren't opinions, they're facts. But don't take my word for it, go talk to your local performance machine shop and see what they tell you.

Bottom line is if you build the engine and break it in right, you'll have a motor that will last as long as you want it to with proper fluid/filter changes. It can be a daily driver or a hot rod either one depending on how you want to drive on any given day. My truck is a hotrod, a mud runner, or a workhose all at the same time and I have all the factory accessories including the A/C. What more could you ask for?

So, I ask you, why would you spend more money to change your truck over to a used stock LS based engine when you could build a brand new roller cam torque monster from the block/heads/pistons that you already have, drop it right back into the truck as is and drive it however you choose for as long as you want?

This is just my own opinion based on my own experience after 20 years of building performance engines. You can take it or leave it. The decision is ultimately up to you. Either way you go, have fun with it and best of luck to you! :metal: