[Walt Fricke]

Robert - your question is a bit obscure (and thus was misunderstood), because only guys making race motors care about weight of this sort. It is unimportant in stock motors.

So much so that I believe at least the following valve train components are the same from 1966 (or soon thereafter) through 1989: The height shims (maybe the wider OD ones came later), the base cups, the inner and outer springs, the retainers, and the keepers. The seals have varied a bit, but since all these valves were 9mm stemmed, they interchange as well.

This is convenient if you are working on motors of this time frame. A keeper just jumped onto my floor, and I couldn't find it. Aaaaargh. But luckily I found one in my valve parts tray. I keep hoping I'll find the other one, so I can put it back in the tray and still have a spare.