Dr. Jeckel

iTrader: (12)

I know most eveyone is running patriot duals or some other kind of dual spring but I was wondering if the PAC 1218's would work too?

The engine setup will be a 5.3 (might have it bored to 5.7 specs), stock crank, stock rods, forged pistons, stock 317 heads, LS6 cam, mp t76 turbo and a maximum of 16-18psi of boost. I do not plan to go over 6400rpm as I am pretty sure the power band will be done by then anyways. The car is not a daily driver and won't see more than 1-2k miles per year of driving and some track time. Typical boost will probably be in the 12psi range, but will have an electronic boost controller to turn it up.

The PAC spring are rated to .600" lift, so should they hold up to that kind of pressure and around 600-700rwhp or am I going to have to worry about valve float and loosing seat pressure?

Thanks, James

hellbents10

iTrader: (10)

They come out to about 130 on the seat which is a bit light for that kind of boost. With a heavy stainless valve no....stock valve it might be OK. I would shoot for 155 on the seat with a LS6 cam and up to 20psi of boost.