Looking For Valve Spring Advice

I'm looking to put valve springs on my W-5s
and need spring.. looking for something like
1.55 dia with about 150 on seat and a 2" install
height.. any ideas.. this is for a FT cam so I
am pretty new to them.. also for you guys that
do heads.. how long will the vac hold.. its a new
valve job.. if I put the vac to it and then shut
off the pump how long will it take before the plate
falls off(just a guess) on one it will stay on
for about 25 seconds and another about 12 seconds
thanks
EDIT
Also I'm installing new seals and wonder if you
guys put them in hot water before installing them
thanks again

If you go with an installed height just a little lower lots of good choices --Marsh has an Isky spring that is fantastic on bigger FT's Comp 928 ain't bad with lite weight retainer

I do have lite weight retainers for it.. how much
less pressure are you talking..10# or 40#.. just
asking
thanks

Whats the spring pressure for the 928 at 2.00
still am not finding much.. I also looked at
the Isky stuff but they are a lot higher spring
pressures that I see
thanks

na that Isky Todd has and the 928 go in at around 1.950 and are around 145 seat and 345 open just depending Indy always sent out 928's and we would shine the retainers and locks in race engines--the 928 could not keep up with a 650 solid or a hot 590 with lots of RPm so Todd found this Isky that works much better in race application ask him part number I can't remember 145 345 or little higher works with lite retainers like Titanium or lite steel Comps