Mike Cordero

iTrader: (122)

I have a 6.0L engine (LQ4) and was thinking to increase the compression so got a set of LQ9 pistons but I was thinking to use LS3 type heads so I'm planning to use the LY6 pistons which have the valve notches already. With those stock pistons and the LS3 heads, how higher I can go with an up graded cam (how much lift)?

UOP

The notch in the LY6 pistons is for the exhaust valve, and would give the same compression as the stock lq4 pistons. Not worth it imo.

The stunningman

iTrader: (47)

^ what he said

You will have 2 exhaust valve notches top and bottom on the LY6 pistons. They will have less compression than a regular LQ4 piston. I would just use the LQ9 pistons and have them flycut or do them yourself. There are write-ups on it.