6.4 LS1 Possible?
6.4 LS1 Possible? Whats the largest LS1 engine bored and stroked? Im looking at going to look at a car ( C5 Corvette ) the owner claims is a bored and stroked "LS1" but he says its a 6.4.. is that even possible? He says its an aluminum block.
Any info you guys have to tell me what to eyeball I appreciate.
I know it has Trick Flow heads and a Fast LSXR 102 but thats about it. I just want to be able to ID what platform is in the car.
Most importantly, do 6.3/6.4 LS1 builds hold up compared to going 6.0 etc or is it borrowed time on that many cubes out of an LS1?
Any info you guys have to tell me what to eyeball I appreciate.
I know it has Trick Flow heads and a Fast LSXR 102 but thats about it. I just want to be able to ID what platform is in the car.
Most importantly, do 6.3/6.4 LS1 builds hold up compared to going 6.0 etc or is it borrowed time on that many cubes out of an LS1?
Last edited by LS1Silverado05; Apr 2, 2026 at 06:33 PM.
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I'd really want receipts from the engine builder. Typically LS1 engine blocks aren't sleeved and stroked to 6.4 cubes. Basic LS1 can't do more than small hone due to the thin block sleeves. And cylinder sleeve length on the LS1 stroke wise is not good.
I'm thinking that 392 cubes is like a late model hemi?
Contact Steve at RED on a stroked / bored LS1 to that level.
I'm thinking that 392 cubes is like a late model hemi?
Contact Steve at RED on a stroked / bored LS1 to that level.
IF this is an actual LS1 block…just thinking configurations here…it could potentially be .005 over, which is the service limit on that block btw, and a 4.1” stroke. That would be a 392, or a 6.4 liter. You’re gonna want to ask questions here…lots of them, and see a build sheet to figure out how he got there.
LS1's used to be resleeved back in the day. Race Engine Development (R.E.D.) did it back then, I am not sure if anyone else did. But a resleeved LS1 definitely was a thing. Maybe a C5R block?
True. Steve did wet sleeve quite a few back in the day. He won’t touch one today. Too many issues. It’s a possible configuration that this C5 could potentially have, but you’d A$$ume that it would be a 427 if it were a sleeved build. Hopeful here that the OP lets us know what this mystery build is.
I had one, Darton wet sleeve by Steve@RED. It held up well for 30,000 miles. Only problem it had was a VERY slight coolant loss. Had to run Evans coolant, and add maybe a pint every 2 months. Never found out where it was going. There was great debate on longevity/long term reliability back then. At 30,000 miles my thrust bearing was shot-.028" endplay, which triggered the crank sensor code. A couple of renowned engine builders claimed that the integrity of the block was compromised, and at WOT the block was distorting and twisting, putting a huge load on the thrust bearing. So I went with an LS7 block, which wasn't available yet when I started the project...
Last edited by grinder11; Apr 3, 2026 at 08:36 AM.
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From: Wilmington, De
383 LS1s were pretty common, and work out to 6.3 liters. It's possible the seller is mistaken, fat-fingered the ad, or bumped it up to 6.4 in his head because he has some sort of inferiority complex around Scat Packs.
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