i know this has been covered before. just thought i'd show my cheap technique and explanation.

remove your rocker boxes and check the endplay of the rocker arms. book says .004-.025. after reading multiple threads on here, I went for .008 on all of them.




i measured them while in the rocker box. then again once out, both measurements were the same. ignore that the feeler gauge is behind the spacer in this pic. i decided to do this write up after someone didn't like my sped up video on Facebook. took the pic in haste and wasn't paying attention.



you don't have to put them back into the rocker box to continue checking end play. simply place a piece of pipe, or two large nuts, or a stack of washers to take up the space and tighten the original nut down



here you can see the shoulder that the spacer rides up against. so this works by opening up the inner diameter of the spacer so that it can recess onto that shoulder and close the gap towards the rocker arm



here's the bit i used to countersink the opening



take your time and continually check fitment. probably put it back together 5-8 times to ensure i didn't cut too much. but if you do, just flip it over and try again



once you put it together and have around .008 clearance you're good to go. will make a nice quite top end.

 

if you make them too tight the valves run lean as you are using guide seals yes /// shovels started out without seals than switched to them so no seals tight /// seals a little loose

primary oil pump oil goes to the top end for a reason // secondary goes too the rod bearings