Got a couple questions about the 5.3L. First, is it possible to sleeve the block and get a bore size of 4.125"? I heard somewhere that you could, but I dont know how reliable that info was. Next, who should I call to get a forged reciprocating assembly for the engine? I'm going to be putting about 9-10 psi or more to this engine and I dont want to worry about melting or cracking a piston, breaking a rod or twisting a crank. If the bore will indeed go to 4.125". that'll be about 387ci with the stock stroke... Yum. Hopefully with the extra cubes, the boost and that cam, I'll make close to 550hp or maybe a smidge more. Well, thanks for any ideas guys!

 

resleeving ls1 blocks runs ~$2600. I'm not sure it can be done to the 5.3, but it would be a sweet alternative to the $6300 C5R block.

if you can sleeve the block to 4.125", just throw in the 4" eagle rotating assembly and have a full 427" engine...

 

I know the 5.3L can be bored out to a 5.7L without resleeving. Don't know if that will give you what you're after or not.

 

You can bore most 5.3/4.8 blocks 0.120 over. But you'd better have it sonic tested first. That yeilds a .010 over LS1 bore of 3.908". That way you can use off the shelf .010 pistons. Couple that with a 4" stroke and you get a 383. Actually its like a 383.8 or something.

 

Here is a very helpfull link on the genIII engines.....engine

 

What's this sonic test I keep hearing about? Just to make sure the walls are still thick enough or something? Im thinkin bout finding a 6L in a wrecked 3/4 ton rig so I can get the 4L80E with it (Just a smidge stronger than the 4L60), and boring that .030 over and a 4 inch stroke to make the 408. Also, who makes a good rotating assembly? I've heard Eagle has had a few problems in the past with the old 350's, but that could be just the opinion of the builder I was talkin to. Never anything bad about Scat, tho. Does Scat make stuff for the gen 3 engines? I may put a blower on this as well, whats a good blower cam for these engines? I have the GM Hot Cam in it right now, what would it do with a blower, and would it swap in to the 6L? Oh, and just for grins, how is a 15.1 quarter mile time for having a cam, headers, custom tuning, true 2 ½ inch dual exhaust and cold air? It was kind of hot when I ran it and the truck has a stock coverter with that cam, so it doesnt exactly jump off the line, it waits till about 3k or so before it starts pulling well. Thanks guys!