slowlsx

iTrader: (28)

I was curious if anyone has made one or does it depend on the combonation?

I just put in some br7ef in my stock 5.3 and plan to run 15-18psi... When i get to 20+psi should i switch to a 8 or 9? This will be on race gas or meth (undecided) abd 9.8:1 compression.

Twin turbo c5

Those 7's should be fine ive been to 18 psi no problem . I've even used tr6 up that high.

FASTFB

iTrader: (24)

The best way to tell what heat range your car wants is to read them. Start with a 8 and make a wot, kill motor pull plugs and see what it wants. You can tell by a couple different ways on the plug. The strap and the threads. Colder the better IMO.