SydwayZ

What is the maximum lift for the stocK ls3 rockers? I have PRC aftermarket ls3 heads with .675" springs. The heads flow the best around 650 lift and higher.
I guess I'm trying to ask at what point are roller rockers needed? Also does going from a 1.7 ratio to a 1.8 ratio have a big effect if any? I'm trying to figure this out before having a custom cam made. Any input is welcome.

build is for Pro charged 408

SydwayZ

Does anyone know anything? You don't need to vote. I just need some advice.

1989GTA

The most I have seen is .630". The problem is getting to close to the end of the stock rocker arm.

SydwayZ

Yeah, I heard 630" too, but I've also heard .650" a lot also. One guy on here (can't remember his name) pushes his to 661"

DietCoke

iTrader: (18)

Maximum you can run, and maximum you can run and not expect to wear out the fulcrums are two seperate #s

A.R. Shale Targa

iTrader: (2)

A buddy of mine runs the factory rockers on PRC heads with I think a .624" Texas Speed cam and the rocker tips look like **** after a season of street and auto cross racing. Not the exhaust side but the offset intake side.
Since you're running forced induction anyways I'd stick to around .600" lift

SydwayZ

Okay thanks