PV timing?

[Fred1956]

I'm back... I got the silencer cleaned and repacked, thanks Glenn!, and now I'm on to the next problem(?)
I changed my 250 to a 274 not long ago and while it runs great and I have no power complaints, jetting is very strange and I'm having trouble wrapping my head around it- MJ 160, PJ 35, AS 1 3/4 out needle JD red in middle clip. Engine will idle forever, good power throughout the range & WOT plug chops are darker than tan but not as black as they were with a 170MJ. At the last HS it got ran WO a bunch as we had several long straights that were WO in 6th for 20-30 seconds (gearing is 13/51). I called Ron at RB Designs, he did my carb, and he wondered about PV timing thinking it could be mimicking a rich condition. I have no service manual and my search on this site finds no reference to timing the PV. Does it need timed? Or just adjustable slack? & shims behind the spring?
Given others' issues with jetting I guess I should just be happy and move on but just the thought of a 160 when everyone else I way bigger makes me a little nervous. Any ideas? Thanks