I made the aluminum parts. The plastic parts are from a Made For You kit.

I used Comp Ultra rockers, thicker cork gaskets, short poly locks and I cut about .100 off the hex head of the(4 on each side) poly lock. The clearance issue on mine was the tall row of adjusters through the center of the head. The big boxy square aluminum rockers have clearance issues, on factory covers, in the rear corners, I've been told they grind the corners of the rockers for clearance.

I have the Comp Cams roller tip rockers also for my upcoming '67 L78 engine build. I have stock chrome covers with drippers that I absolutely refuse to cut the drippers off of! This will be a close to stock build. I have the Crower short polylocks but I'm afraid they will get in the way of the drippers.

As a back up, I just scored a NOS set of GM 1.7 ratio steel rockers (these rockers are the GM replacement for the original "L" & "H" 1.7 steel rockers for SHP engines). My '67 L78 came with the "L" steel rockers.

I will likely give in and just go with the steel rockers, but I may try the roller tip rockers just to see if they clear. My bet is they won't, and I don't like the idea of doubling up on the gaskets. I will be running the original silver coated cork valve cover gaskets. My engine will look bone stock.

I'm hoping my Comp Cam 3/8" pushrods that came in the roller tip rockers kit will work with the steel rocker arms.

My valve covers have the dippers and they are not a issue. The poly locks are the contact point with the valve cover.