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Old 01-11-2013, 06:23 AM
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Originally Posted by cobalt327 View Post
To confirm, the rockers are hitting the retainers, not the split locks, right?
The first pair of heads we installed were equipped with Ferrea 5000 Series valves with .256" tips. I am using Scorpion 1.5:1 SA narrow-body rocker arms for center bolt valve covers. With that set up, the alignment rails on the rocker arm roller tips actually rode ON the Comp Cams 10* locks (not the retainers) and did not even touch the valves. We switched to Comp Cams 10* locks designed for lash caps but did not use lash caps. Those keepers provided about .005"- .010" clearance between the rocker rails and the keepers. The rocker rails sit in the lash cap cavity but would pinch against the locks and eventually fail. Not good enough.

I drove it for about 4,000 miles using the lash cap keepers but I checked the keepers and rocker rails regularly. I prepared a better set of heads and this time I used Manley Race Master Series valves with .290" tips and used regular Comp Cams 613 (10*) keepers. Now the rocker rail to keeper clearance is .035" - .040" which is the way is should be and the way the SA rocker clearances were designed by GM.

It does not matter whether you are using beehive valve springs and retainers or straight springs and retainers, the clearances or lack thereof are the same. You must use valves with .290" tips with SA rocker arms. I preferred to use Ferrea 5000 Series valves but Ferrea does not offer Chevy valves with .290" tips, at least not in the 5000 Series. So you must use Manley Race Master Series valves with .290" tips and they cost twice as much.

The alternative is to get a flat bastard file and go to work.
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