not familiar enough with the small block to know but I am working on a 1970 318 and the exhaust valves are of equal height and are also higher than the intake valves around a 1/16th of an inch more or less. i did not measure it. Is this normal?

Installed valve spring height should be right in about 1.68 (1.67-1.70) Relatively level across all 8 valve stems per head. If they IMO the valves are not in the seats correctly. either too deep for some or not deep enough for others.

I would have that they should be equal also. I did measure the difference and the intakes are between .065-.075 lower than the exhaust. It's as if somebody set the stem height that way. The engine has been rebuilt at some point.

Why would they. The spring is what is set to installed height and they are all (intake & exhaust) set at the same installed height. What you are getting is a seating variance as I stated above.

Or somebody doesn't know not to bear down on the seat grinder. Personally I would have them done right. The exhausts will not last long cut into the head that way. As a rule Mopar heads seem more tolerant of UL gas and seem to have a harder seat than brand X but once that surface is cut down like you say it is not a good thing and they won't last long.

It seemed to me that all the heads came this way from the factory. If you are running a mild hydraulic cam, it will compensate for the difference.