ridnhood

Getting ready to order an lsx block and rotating assembly. After running on nitrous this year I'm hooked and want to build a nitrous motor around 427 inch. I already have ls3 heads but want to go with a bigger cam. I can get a higher lift spring for the 3s but at a hefty price, or can go for the 7s with the bbc springs also at a hefty price. I guess what I'm asking is would the 7s be worth 3000+ bucks or an extra 1000 put into the 3s.

ZONES89RS

iTrader: (25)

The LS7 start at 360 cfm if I remember right, that's where the LS3 heads max out and the ls7 can hit 390 ported.

NemeSS

iTrader: (127)

a good starting point imo, would get a custom grind w the exsisting ls3. run it. see how it does on motor n spray n go from there. at least u will have a baseline. and if the money is burning a hole in ur pocket, get the hi price heads.