I've got a set of 416 heads from an 83 TA that I'm putting on my motor. I've also got a Comp Cam XE268 kit that includes new springs and retainers. I have yet to disassemble the 416s, but I should have rotators, correct? If so, how much should I shim? Or is there something else that replaces the rotator?

BTW, what the heck were the rotators even installed for? Was there a real purpose to them?

 

Nobody?

 

trash the factory parts, use the aftermarket retainers. measure the installed height, might not have to shim anything, or might have to shim every one, but i doubt it.

 

When did they start using rotators? These are 83 heads. I haven't taken an extremely close up look (I'm kinda sick right now, and the garage is cold), but it looks like the springs on both sides look the same (same caps, same height). I am admittedly eyeballing it from a distance. I'm just wondering if I should order some shims or another alternative to the rotator.

 

you should do what i said

 

Like ede said, the best place for those rotators is the trash can!!!
And to answer you question they were put on there to cause the exhaust valve to slowly rotate as it moves up and down to increase valve life, but all it really does is add a lot of weight to the valvetrain and lower the RPM that valve float will occur.

 

What year did they start putting them under (over?) the springs?

 

about 74

that's enough cam that it's worthwhile to measure everything; as parts wear, the spring installed height changes, which in turn affects how much shim you should use; particularly as the valve seats wear (or are ground) the valve moves up in the head, the installed height gets too high, seat pressure is too low, instant valve float