Looking for some thoughts on some stock heads I'm working with. The motor isn't really anything special, but an 8-71 is going on it, and I'm following a build done by chevyperformance some time ago.
I'm working on freshening up some stock 454 heads, where I found valve rotators on both the Exh and Int valves. I didn't know they put them on intake valves as well... but oh well. So, I was planning on using some Comp .300 eliminators when I got down to measuring.
My springs call out for a 1.9" installed height. From the head, the spring retainer measures in at 2.2" on the exhaust valves - so I'm good there with the rotator eliminators, bringing be back to the needed 1.9" installed height.
On the intake, I'm getting anywhere from 2.160" - 2.175", which when using the eliminators, puts me in the 1.860" installed height range.
The cam has a .3220 lobe lift and I'm using summit 1.72:1 roller tip rockers, putting me at .5538" lift. Coil bind on the springs is at 1.2" per Comp. Even at the 1.860" installed height, with the .5538" lift, I'm looking at 1.306" compressed height at valve lift - .1062" away from coil bind.
The reduction of the .04" will add about 15# of seat pressure which per comp is 122# @ 1.9", making seat on intakes 137#.
Is the .1062" from coil bind acceptable?
Is the additional seat pressure on the intakes acceptable? There is a blower on this motor.
I think I've seen offset retainers that come in at .05", but then I'd need a shim on the bottom with the valve rotator eliminator, correct?
Retainers: Comp 748-16
Locks: Comp 612-16
Springs: Comp 911-16
Cam: Comp 11-404-4 .3220" Lobe Lift
Rockers: Summit 1.72:1 roller tips
Thanks to anyone who responds!