Well 243/799 heads have pretty good compression without being milled. I wonder why they would do that unless they built the motor for E85 or race gas. Especially in California with our horrifically poor cat piss 91 octane.

LS1 heads are 10.1:1 stock 68cc chambers
LS6 heads are 10.5:1 stock 60cc chambers

Hopefully they didn't mill them too much. If they didn't, you might be able to rectify the situation with a thicker gasket.

If a bore requires new pistons, and the static comp is really high and I can't use a thicker gasket, maybe I could use dished pistons? Or is that just silly on an NA?

Gotta see what the head chambers are at first. It may or maynot be the issue. 11:1 isn't high enough to cause knock. You may have a tuning issue. But if they milled them down too far, then yea, I'd maybe run a dished piston. But at that point, you'd have to think about what kind of money is going into that vs getting new heads that haven't been milled to death.

Nothing wrong with running a dished piston on an n/a motor.

Have the heads cc'ed before purchasing pistons or head gaskets.

Don't run the LS7 exhaust valve unless you want to do this again from scratch.

Well, #3 hat a broken ring and it gouged the wall pretty good. The shop will check, but the bock man not be rebuildable since there is so little to work with on an LS1. #1 had a little coolant in it, so not sure where that came from. Booh. Dropped off the block and heads today. Will have an answer by the end of the week.

Won't bother with the LS7 valves. Not sure what's in them, but they look pretty big already.


Question is if the block is not rebuildable and one of the heads is shot, WTF do I do then. . .

That sucks. But I do have access to a LS2 block for you $700 and I'll drop it off. Or I can get you a whole 5.3 to drop in there.

Thanks for the heads up.

Do you mean bare block for the LS2 or does it have the rotating assembly? Also, off hand, what's the interchange between the LS1 and 2 for things like heads, intake, accessories. IOW, how much of what I have could be used?

Forgot to mention, cam is toast. ls1z28 said the springs were probably way too strong for it, kind of obviously worn, and one of the lobes is chewed up.

Holy fuck, I though Ron and I were the only ones who fucked shit up in odd style.

I really hate to say it, but the hotrod kit from GM with the LS3 is probably your best bet.

Unless you know something I don't, those are more or less $8k when you're done. On the upside it'd be brand new and about as "bullet proof" as it's going to get for the same or even more power.

As much as or more than the scratch for the motor, I shudder at the idea of integrating it with my LS1 ECU and programming.