[redmodelt]

RE; Snyder's recommends .010" clearance but that is more than I would like.
The is the lifter to stem gap not the stem to guide clearance.



For stem size new valves; Original style with the pin; they are made for one of 3 sizes std, .015 OS and .030 OS. The reams sold for the two over size, I have had no issues with the original style replacement valve using the ream as sold in the engines I have rebuilt for customers with the stock cast iron guides.
The modern type sold in most catalogs is .030 OS but the catalogs list a different ream for them so would guess not quite the same as the pin type .030 OS.