engine build questions

[garagemethods]

i've been registered to the forum for a while, but i'm now posting in hopes for some serious help.

i'm looking to build an engine for my 1996 c1500 ecsb 5.0. as it has the 5.0 that isn't the greatest beginning for a performance build, so i plan to build up a 5.7 to swap in there. i understand that the only difference between the two when it comes to swapping is the tune.

to start off, i planed on buying either a used or new 350 short block and building up the top end (heads, intake, cam) or using the stock vortec heads and just doing an intake and cam.
so the first thing i need help on is, should i buy a new or used 350 short block? what are the perks to each and what are the negatives to each.
secondly, what kind of power should i expect from each idea (complete top end vs. just cam and intake)

i'm very new to any kind of engine building so please bear with me on this, and point me in the right direction

 

[Butch]

If your willing to drop the cash on a new block and building it then I highly suggest looking into re-powering with a LS block (5.3, 6.0, LS1+) with a cam and tune you'll make more power with a flatter curve. The L31 (5.7L) has major flaws with the intake limiting its response to power adders even though the bottom end is pretty stout, but there are a options available, check out Aloicious, but for the money it requires I recommend starting with more efficient base. You'll find a lot of information on this site under LSX & Carb Swaps, many members have done the swap to both 5.3s and 6.0 and many more of us are planning on doing this same swap in our rigs rather than building our L31s. Just an option I wanted to make sure your aware of, don't take me wrong the L31 is a stout little motor with a lot of options and cheap parts but the LS block has proven itself as a viable, cost effective option with GMT400 trucks.

 

[jcro61]

I would find a running 5.7 vortec. Swap it in and swap the computers and be done with it.

 

[garagemethods]

i have thought about a 5.3 instead of a 5.7, but the fact that the 5.7 just about bolts right in is dragging me straight to that option. and as for the fuel limitations i would most likely just swap to a marine intake if i went that far and needed the extra fuel.

so what kind of power can the 5.3 make with just a cam and tune? it seems like WAY more money to do the 5.3 swap so i still don't know.

as for the 5.7, what kind of power is expected from it with just a cam and tune? or a cam, tune, 1.6 rockers, the marine intake swap, and some edelbrock etec heads?

 

[sliggett]

I would find a running 5.7 vortec. Swap it in and swap the computers and be done with it.

would you have to swap the engine control harness with the computer?

 

[jcro61]

i am not sure but i am gonna go out on a limb and say if its from your same year probably not. Putting a stock 5.7 motor in would be your best bet. You obviously do not have a lot of experience to do much of the work yourself so doing a lsx swap will end up costing you what you could buy a nbs truck for. once your truck is up and running with the stock vortec 5.7 you could try out something like a blackbear tune and see if that satisfies your needs at this time.

 

[garagemethods]

alright so i think i have what i want to do.

buy a used 350 short block. throw on some brand new vortec heads. use a new or the used factory intake. add a cam. and of course have a tune done.

now though, i understand the max lift on the vortec heads is only .475" of lift, but whats the biggest (while still being safe) that i can go with using the vortec heads without any machining and using the stock torque converter? i'm willing to use different rockers and springs and whatnot to net higher lift.

what are some reasonable estimates of power with a setup like this?

and please tell me if theres anything missing and anything else you may want to add.

 

[93Chevy_1500]

The biggest cam you can go with is a Comp Cam 270H I believe. I put that in my S-10 with a 355 and it said it was the biggest you could go with the stock converter. Has a nice lump to it. I like it.

 

[garagemethods]

The biggest cam you can go with is a Comp Cam 270H I believe. I put that in my S-10 with a 355 and it said it was the biggest you could go with the stock converter. Has a nice lump to it. I like it.

could you give me a little more info on it? i saw two 270h's on comp cams website when i seached it. maybe a product number?

 

[93Chevy_1500]

I can get it for you when I get home. I ordered it from summit racing the price was around 109$. give or take.