I have crane duble coil springs installed at 1.80 and my seat presure of 125 closed and at .600 is 360 will this cause valve float with my cam (612/615 242/248)

 

I don't honestly know, but the Cranes can be shimmed if you need more pressure. Also, did you measure the seat pressure or the installed height? At 1.8, the advertised seat pressure on the Cranes is 112 lbs so if you are measuring 125 lbs your installed height is more likely around 1.76".

Also, what RPM are you concerned about float as it will be RPM dependent.

 

I found out im gona need .030 shims where can i buy them

 

Well, funny but Crane doesn't make the shims. You can get them from Comp though. You want the 4742-16's. They go under the spring seat, so if you have already installed the springs and seals, you will need to take it all apart again. You may need new seals in case you damage them on removal.

Comp shims

 

or i could use these
Crane shims

 

PS i no there .060 but i still will be safe from coil bind

 

Those won't fit, the OD is too big. They don't make shims for the LS1, you have to get the Comps.

 

Right, the biggest O.D. you can go is 1.38" on the shim unless you have the spring pockets machined bigger.