I have a 98 formula w/ 113xxx miles.I'm looking to do a turbo build and want to forge the bottom end.I heard 98 ls1 blocks have thinner cylinder walls and aren't as good to bore/hone. Anyone know if this is true. I would like to do the build with this block.I don't want to buy another one, for many reasons,but mostly cost.

The 98' blocks do in fact have a thinner sleeve than do the later model years. However, you can still bore/hone them. You just can't go as far with the bore. Most forged pistons that you go with will ask for a bore size of around 3.905" though which is perfectly fine for the 98's...

I went with Diamond and that's what I bored mine out to. Hope this helps.

98 Redbird is 100% correct. Most all forged pistons require you to hone the bore a bit anyway.

Thanks guys, I was looking at diamond 3.905 pistons w/ -8.6cc dish. I guess these will work then. I'm relieved to hear that this would be o.k. for this application!

the 97 ls1 that first went in the corvettes could tolerate even less couldnt they? i think it was only like .005 over, but the 98 one should be ok

sell the undamaged 5.7 and go with a 6.0 iron block,
pistons will be in the same price range, 3.905 or 4.00 bore really, not much diff. if any

Isn't it possible to re-sleeve the block? Many years ago it was not possible to do this, but it seems the tech has changed. If so, can't you add a different sleeve that will accept a wider bore?

might as well go with aftermarket block, the ONLY really good block re-sleevers will use darton sleeves, + machine work = new aftermarket block

This is actually good advice. They dont make the LS1 block anymore and good ones are going to be and are getting hard to find. The 6.0 iron block is much better for boost anyway. Iron doesnt distort the way aluminum does.

Anybody have a 6.0 block w/ crank to trade for an ls1 shortblock? Or possibly the longblock plus $$$.

put it up for sale!

It's not mine, but passing along what looks like a good deal to me. If you are interested, shoot me a PM and I'll have the guy get ahold of you.


2002 LQ4 6.0 shortblock
I took the motor apart to check all the clearences and clean it up. Everything looked good so i put everything back together. The motor has 70,000 miles on it.
$650 picked up

I am in Ofallon Mo.

I think the shipping would be too much for this block though.I'm looking for a trade for my shortblock.Thanks anyway 02 blk ws6

check your casting number, u may have a windowed main webbing block,
aka as ls6 block, if its a true 02' model.

or just rebuild it like you originally planned with forged pistons and 317 heads for psi ready motor