I had a leaking off brand electric pump that had a place for the heater core hose, but when I replaced it with a Proform I never bothered to check if it had the same thing. Of course it does not. Can I run that hose to somewhere on the radiator? I'd hate to start over with a different pump. Worst case I go without heat since it's stored all winter anyway, but I'd like to find a solution.

Radiator

Pump

Yup, if you have the nipple for it on the rad's cold tank (pass side of the car) you can run it there.

Another possibility is to tee off the lower rad hose.

Really, anywhere on the cold (suction) side of the system, is OK.

Might be possible to drill & tap the new pump body for it. It's kind of a no-brainer; ½" pipe. If you post a pic maybe we can tell you where you could do that.

The spot with with plug should do the trick then?

Yup.

Interesting that there's already another hose on that other nipple.