spring pressures brad 5 and c screw

brad 5 cyl heads
c screw blower 115 od 47 psi boost @9000
what spring pressures should i be running
intake
exhaust
ive been using 050 erson on intake @2.100=480lbsnew, 440 after 10 runs
and 050 erson on exhaust @2.100 =480lbs new, 450 after 10runs
on my older brad 5 heads (square groove valves)

but i just got 4 newer heads and can only
get 2.00 with .050 spring cups (mti or sps) on exhaust
should i use 048 erson on exhaust because 049 will be 540lbs
these newer heads have conway #3 victory retainers
and the keeper are radial groove and are already offset down compared
to the intake keepers
maybe the valve is too short
im afraid to cut head seat looks close to intake port already

so if i lost ya
i just need exhaust spring pressures that would be recommended
for my brad 5s and ill get the height some how
thanks