Boost valve recommendation

[BEATAV8]

My car is pushing 130mph in the 1/4.

Trans shifts OK manually, but there are 2 issues otherwise (gear selector in "D").
1. WOT shifts are to soon by itself, only ~5200RPM. I'd like to see 57-5800.
2. WOT shift is to soft if it shifts by itself (mainly 2-3). I'm worried I might torch some clutches. It has dual feed / increased feed to 3rd.

It has a .500 boost valve. I'm looking at moving up to a .555 and then modifying the governor afterwards. Good plan?

Pic shows auto 1-2 shift and manual 2-3 shift.

 

[Syclone0044]

I suspect that the larger boost valve will increase pressure, firm up shifts, and raise your auto shifts since the governor has to overcome the line pressure to shift.