LS Noob question

[CC69Rat]

I have an oportunity to purchase a complete ( but currently apart) 02 model 5.3 with the harness and 160k miles for $400.

I would go through a 60k mile motor if I had one and bore it, general rebuild... so 160k.. is that a major problem?

Would this be a good start? Maybe ls2 heads, z06 spec cam, etc. How/ would that all play nicely? Your thoughts? The engine is out of an 02 Silverado.
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[theastronaut]

LS2 chambers are set up for the LS2's 4.00 inch bore, which won't work on the 5.3's 3.78 inch bore. For a little more money I'd find a complete engine with less miles that hasn't been taken apart. An iron block 5.3 can be bored to 3.90" (LS1 size, 5.7) if you're going to rebuild one.

[Jon01]

160k is quite a few miles.
I think you can find a better deal, especially with it benig apart - I paid $500 for my LM7(iron block 5.3) with 80k, all accy's, harness, intake to pan...

Per the 1st post, if starting with 5k I'd get an LQ4, 243 heads, MS3 cam, TBSS headers, 4L80, 3200-3500 converter.
This won't get the best mileage but it'll run like absolute stink.
This way you'll have the 4" bore if you ever want to upgradeto L92 heads.

On the cheap, get a 5.3 out of a truck/suburban, make sure to get the pedal, harness and all accy's with it.
Have the heads cut, find a used TR224 cam and stick some Comp 918 valve springs in it.

Originally Posted by theastronaut

LS2 chambers are set up for the LS2's 4.00 inch bore, which won't work on the 5.3's 3.78 inch bore. For a little more money I'd find a complete engine with less miles that hasn't been taken apart. An iron block 5.3 can be bored to 3.90" (LS1 size, 5.7) if you're going to rebuild one.

LS2 heads will go right on a 5.3, you are thinking of L92 heads.

[Jon01]

If you're going to stick a cam in it I wouldn't bother with an LS6 cam, there are much better options out there that can use LS3 springs.
Something like a Comp 230/236, small lobe TR224 or an old GM hot cam.

[theastronaut]

Originally Posted by Jon01

LS2 heads will go right on a 5.3, you are thinking of L92 heads.

Won't the larger chamber drop the compression ratio?

[Jon01]

I should have included 799 heads in my statement above, they come on newer 5.3's and some C6's and are identical to LS2/6 heads(243's)

243/799 head chambers are ~3cc larger than 706/862 heads but that's easily overcome by milling them and quite commonly done.
Port volume and intake valve sizes are larger on 243/799 heads so they will move powerband up but will also make more peak power than unported 706/862 heads with a good camshaft.