Philip,
Unless I misunderstand you I think you have confused push rods and connecting rods. If you have removed the head, re-use the push rods and re-install in the same hole and with the same lifter. Do not mix up the relationship of the camshaft, lifter and push rods. There are no shims on the push rods.
There are actually two types of pilot bushings. The original type is made of sintered brass, the later type has iron mixed in. The better one is the former without iron and the way you tell is with a magnet. If a magnet is NOT attracted to the bushing that is the one you want. At the parts house I used when dealing with this they had both types on their shelves. I noticed that the preferred one had "HD" at the end of the part number, perhaps standing for "heavy duty". I am not sure this is true for other brands, just sharing this in case it helps.
I believe all 37-40 heads are the same, so you can mix and match parts as you want. I would select those that appear least worn.
Kent
Last edited by Lightholder's Dad; 12/22/2020 4:37 PM.
