[oldman]

Originally Posted by Jbanta1983

I've read a couple places 650 is the limit on stock lt1 pistons and he said most importantly he wants it to run safe. At what horsepower would you reccomend pistons?

There is no "safe". You can say the OEM at 560 whp went to forged pistons, titanium intake valve and they have to offer a warranty. For the 660 WHP LT5 they went to AFM delete. So "safe" and warranty are at least getting close to being synoptical. For me one piece valve, forged piston, stronger rod bolt (or rod) and addressing the vavletrain is "safe" at 650 WHP plus, which is what GM did for the LT5 so I'm copacetic with GM. For others bone stock LT1 engine is fine, "never have a problem". Amen. Now I want 100K miles, GM has to provide a warranty even if you beat on it like you stole it. I don't know what power level you can get a roots blower with drivetrain warranty? Lingenfelter offers a warranty on a base supercharger say 560 WHP. So if the shop is going to say no issues, your next question should be about engine warranty. I have OVER 1000 WOT runs on my setups and learned a whole lot.

edit, looks like Lingenfelter offers a drivetrain warranty only on their NA LT1 build, the 630 engine HP supercharger build comes with warranty only on the supercharger. OK then. Hennessy offers a 3 year on their 605 and 750 engine HP (upgraded valvetrain, minimum boost for HP) build, so I would agree that some 100 or so engine HP of head room can be gained by adding headers, ported heads and cam as these don't stress the piston / ring assembly as much. You are still hoping that your specific ring gaps will be enough. Mine ring gaps were good and I never had a stock piston / ring issue, so I would probably still be OK even now on my OEM piston, ring, and / or rod assembly.