I actually suggested the springs could be bad or too light for the application earlier , anyway glad you found the problem , I would still run the lash caps . With the springs being to light the valves could have been late closing allowing slack between the rockers & valves causing them to hammer into the rocker arms instead of staying in contact at all times so the rocker failure was more likely to be effect not cause .
Sorry Neil! You sure did. I've got a couple threads going on different forums, I have a hard time keeping them straight sometimes. Your help is greatly appreciated!
Obviously I'll be taking a look at the geometry again with the new rockers, but I don't think I'll need the lash caps with the Crane's. The Harland's are spec'd for taller valves, I don't think the Crane's are. But I'll have to go through all of that again when I get the heads back, checking the pattern and measuring for push rods. My machinist is going to correct the valve height's, so I'll have to see how that turns out. It'd be nice not to have to order new push rods. But it'd be a lot nicer not to destroy another set of rockers, so I'll remeasure everything and see what I get.
I would have thought that the hydraulic lifters would have made all of this a bit easier, it's amazing that the factory could just slap on non-adjustable rockers, hydraulic lifters, and pretty much the same height pushrods on everything despite the range of build tolerances they had. But this was my first build, and although I tried to get everything right the first time its obvious I still have a few lessons to learn. Fortunately I went a different route with my second build by doing all of the assembly myself and using RHS heads, but you'd better believe I'll be double checking everything on it before it gets dropped in.
