Well the pushrods from both 440's are the same length. Have the heads been surfaced/block decked...will have to check, I dont know. The lifter face is not where the hole was punched, it is on other end where pushrod meets. The lifters I pulled from Superbee are a little longer than the ones that I pulled from, another 440. Put the two different lifters side by side WITH the shim on top of shorter lifter and they are the exact same length. I figured the shims, which are NOT homemade, were added under the rockerarm shafts for clearance??I was told shims were used before ajustable rocker arms were around?