I have a 4l85e im rebuilding for a pump gas 416 LS3 with a ported LSA on it. I am using a ckperformance master shift kit. I am looking to use his springs for the boost valve, but i need a recommendation on which boost valve to go with. Looking for hardest shifts possible, especially because i will have a 3800-4000ish converter on it to soak it all up. Thanks in advance.

 

You can use the CK spring with an OEM pressure regulator boost valve/ sleeve assembly (this is the intended use for the CK spring).

Or

You can use an aftermarket pressure regulator boost valve/ sleeve assembly with an OEM spring.

Or

You can use an aftermarket spring and pressure regulator boost valve/ sleeve assembly as part of a set.

 

I'd go with a sonnax LB1 and the stock spring.
This should net 185 ish psi line
Much more than that is totally unnecessary for even 1000hp

If you want firm shifts, accumulator setup and orifice sizing will play large roles.

 

The CK performance master kit instructions say to drill a .055” to .067” hole between the line pressure and converter charge passages in the pump cover. However if you use the sonnax boost value 4L80E-LB1, you aren't supposed to drill that hole, correct?

Also if you are still at say 600 hp and will eventually have 1100hp, you should use the purple spring in the kit and be at lower line pressure until you actually have the 1100hp correct? At that point one you have the higher power, you would switch to the orange spring / higher line pressure. What happens if you are only at 600hp and use the orange spring?

 

Use the lighter pressure regulator valve spring for both those power levels...

I do not raise the line pressure higher than that until higher power levels (when lower line pressure just does not hold effectively enough).

Sonnax produces a replacement pressure regulator valve that will bleed off line pressure to lube oil (not a boost valve/ sleeve assembly)




If using the stock pressure regulator valve... then you can drill a bleed into the lube passage in the pump.

 

Drill the line to lube .078 regardless of which boost valve
use stock PR valve
Use Stock spring with LB1 even at 1100