Front/rear balance after front disc swap

With bigger rear tires, 245 fronts and 275 rears, I found 7/8 w/c's and no Pvalve worked just fine. With 235s/295s I found 15/16 worked just fine, still with no Pvalve. But I have the KH 4-pistons up front.
I suppose installing an adjustable Pvalve would be the thing to do, and I confess I bought one. It's brand new and still in the bubble-pac 16 years later.