You can keep them. Rebalancing is not a problem. Kent was simply saying sometimes it’s easier to sell what you have as a combo, and buy new. Might even save you money, if you catch the new assembly on sale.

As long as the setup is optimized for the rpm, you’ll be fine. LLSR requires better springs. For the camshaft you’ll need to turn that kind of rpm, you’ll likely need a shaft rocker setup. Depends on camshaft lift numbers. To get the girl to breathe up there, you’ll need a real good intake also. Do your homework, and it will work out.

Tusky, he’s gonna sleeve a GM block, but you are absolutely correct.

lots of guys rev and spray Stock ls7 blocks

But yeah it’s the iron 6.0 blocks that you need to be more careful with for adding stroke on Stock sleeves. They’re short

correction, i have a sleeved block......still havent gotten a chance to take a few pics, but when i popped the cover on the tub, i found the filler neck broke off the valve cover, and on that same cover the gasket was all hanging out like they just tightened it down without lining it up or something.........it is what it is

Whatever erl used......glad u mentioned the "smushed" piston, so i wont consider anything over 4.1 since durability is obviously a concern and dont wanna take chances anywhere on this build

Not exactly, I still have 3 rings on the piston. I helieve Brian Tooley had a 4.250” stroke engine built a long time ago with a sleeved block and I believe there were still 3 rings on that piston design. On mine, instead of using 1.5/1.5/3.0mm like a lot of “basic” designs, I have 1.0/1.0/2.0mm rings like Mahle uses on their shelf pistons. That’s about .080” of real estate freed up for thicker ring lands and/or moving the skirt up higher. It’s still less than 1.00” of compression height, so no nitrous or boost. If I were to do it again, I would probably opt for a more wear resitant 4032 alloy instead of the softer 2618.

I know the one you're talking about, I think that was for James Day’s engine, race only application. He kept that on his desk when his shop was in Houston. Yeah, that was years ago and luckily piston tech has come a long way since then.

Gracias. I learned from really smart guys like Erik and others from when I went to the School of Automotive Machinists years ago. *shameless plug alert*

This is a great post for me because I’m torn between a 3.9” and a 4” crank for my ls1 block. It’s a llsr Mamo 220s and Mamo MSD build, and I want it to last a while, but after reading the article from K1 I’m not so sure if the smarter decision is to go with a 3.9” crank?

I’ll take any advice.