I'll try to explain this as good as I can.
I've noticed that some of the rockers aren't sitting
on the center of the valve tip. If you take a look
at the pic below, you'll see that the RR on the right
isn't centered on the valve tip. It's positioned more
in the right direction (arrow) and roller tip is not
pushing on the whole valve tip but only on the right side
of the tip.

But I don't think that there's much that I can do.
I thought of grinding the holes on the guideplates to
make them adjustable a little bit. But if I do that, than
the other rocker on the same guideplate won't be centered.

Rockers are CompCams Pro Magnums, non self-aligning.
Any opinions?

Things that make you go hmmmmmph!

I bought TrickFlow GuidePlates and they keep everything straight on mine. I have the same rockers as you. It also looks like it sits a bit forward of the valve stem too.

Can you post a photo of the guide plate?

Sure, here is the pic. As for rockers beeing too forward,
you're right. I have to order new pushrods.

Who makes the guideplates? Looks like the forward slot isn't forward enough. Same way on the other cylinder.

ISKY sells adjustable guide plates.

Others have resorted to cutting and re-welding their plates.

DART sells slightly modded plates to address the slight re-positioning of their valves on their PRO1s. DART's site and literature say the slight off-set is NOT a problem. IIRC the offset distance is .030"

Hope this helps.

Jake

All SBC are like this to varying degrees.

Exactly how much varies with the particular head, rocker ratio, etc.

The only way to eliminate it completely is adjustable guideplates.

Thanks guys! I've ordered adjustable guideplates.
I have a big cam and springs and plan to rev it to 6500,
so it's better to be sure!


CC: the guideplates on pics are Competiton Cams product.

When I had LLoyd Elliot do my head work, he suggested I not buy the CC guide plates and by the Trickflow instead. He gave no reason except that is what seemed to be working well with people that used his services.