Help identifying heater box

Hi, working on restoring a heater box for our 71 RR, no AC.
Since we got this car in many boxes, I want to make sure I have the correct heater box before I start.

The stamped numbers on the case are:

3441 398
2890
Do I have the correct box?

Thanks, Joe

I think I'm good, I see one on EBay, same top numbers, different
bottom one (date code?).

Looks identical so I'm ordering the rebuild kit.from Detroit Muscle Tech.

Thanks, Joe

PS Who has had good luck with repro heater cores?
Last one I bought for our 70 needed some serious tweaking to fit....

If you have a radiator shop in your area, they can pressure test it & perform repairs; it's just a mini-radiator. I've had mixed luck with the fit of the repros, even on a '79 Chevy pickup.

I would have done that except for the fact that the hack
that removed the heater box snipped the ends off rather than
doing it right.

Also it looks like it had been repaired before so....here I am needing
a new core.

Thanks, Joe