5.3 LM7 rebuild - is it worth it?

[bdahlg68]

So I can get my hands on a 5.3 LM7 engine for free - just need to pay a few hundred in shipping. It's complete intake to oil pan including coil packs. No harness / ecm. It came out of a 2002 Suburban and most likely spun a bearing and is therefore not running and will need a rebuild. My overall goal is to get to ~ 500hp / 500tq with an LS based motor for as cheap as I can. At first I thought I scored a deal getting this engine for peanuts, but now I'm not so sure. Rebuild + parts could easily go over $6k it seems. Is this still a good route or is it cheaper to go another route?



For reference, I'm more than happy to do the top-end assembly work myself, but feel someone else should take care of any honing / machine work and bottom end assembly.

Any input / experience / recommendations would be appreciated.

[BulldawgMusclecars]

A few hundred in shipping? You could probably buy one locally with no issues for what that one will cost you in shipping. The advantage of the 5.3 is relatively low cost, and 6k would get you a nice crate motor with more cubic inches. Rebuilding one defeats the purpose. I'd move on, and find an engine that doesn't have a spun bearing or need other major work, and save your $$$ for the fun stuff....cam, valvespring upgrades, intake, etc.

[bdahlg68]

Not even wort the parts like front accessories plus scrap? I'm thnking I'll have it shipped out and sit on it. Use it for mock up or parts scavenging later on. Then I'll just part it out.

[sumnerslayer]

Aug 2011 super chevy took a 5.3 and stroked it to 383 ci, topped it with rhs pro action ls1 heads, comp cams xfi rpm cam, fast intake, 36 lb injectors and made 506 hp@5700 and 503 lb-ft@ 4700.....nice numbers. For same setup with stock ls1 heads made 465hp@5500 and 485 lb-ft@4400, could be a stout motor if you ask me, and if the bottom end needs redone anyways all the more reason to make more cubes while your doing it!

[bdahlg68]

I think I figured out a bit why people feel it isn't worth it. I talked with Texas Speed and was quoted 875 for the machining. Well for about 1000, I coul have a new LS2 block. In either case I'd stil need everything else so the difference wouldn't be big. I may just go the stroked LS2 route. Either way I think it'd be worth getting it out here for mock up and some part scavenging as well. I could then part it out and probably cover the shipping cost.

[jgpclone]

lq9 would be a better buy locally but gl on what u go with