Is it really possible to overheat a Smallblock pretty fast without enough timing? You’d think it wouldn’t run or even be smooth. 2000 rpms it runs hot in 5 min. I need to get timing tape on it to see where it is. Timing by “feel” isn’t working.

I's start looking elsewhere at the cooling system but you really do need to get the timing correct also.

It may not be related, but I changed up how my timing works, and mine seems to run a lot cooler on the highway now.

Or get a dial back timing light and forget the tape.

0.0632683" is (1) degree. measure out a strip of paper for how many degrees you need. IE 2&1/4" (2.246") is 35.5 degrees. How hot is "hot" Confirmed with a good mech gauge? is this a new ring breakin? I'd think 30 deg (1.898") at 2000 RPM would be enough to keep it from overheating from retarded timing.

YES. I think alot of old cars overheat because their owners won't check the timing or don't set it correctly. When its too retarded more of the bore is exposed to more flame front, and you get more heat transfer into the coolant.

Vacuum advance helps too. With stock type timing curves removing the vacuum advance will often cause them to run hot.

To little as well as to much total timing will make motors run hotter than when there tuned properly
Do you have access, beg, borrow or rent, to a dial back timing light? If so get it and let us know if you need help on how to use it to set your timing correctly

and to add to what was said, too little timing can feel smooth.