Most motors that do not have mounting feet and some that do have what is called C-Flange mounting that works off the shaft end that you didn’t supply a photo of. There are numerous adapters made to mount to the C-flange and some give it a mounting foot even. Some devices have the C-flange built into it and you simply attach the motor when doing a replacement.
What does the shaft end look like and what does it look like where it is going?
There are also belly bands that clamp around the outside sometimes. If they sent this as a replacement and it doesn’t look like the right thing compare the numbers to the old motor.
Are the 4 holes on the non shaft end marked with the black dots tapped holes? If they are maybe they are to be used to attach the motor to the grill. It looks like the old mounting is with long thru bolts and nut to the grill. In your picture I only see two holes on the shaft end and four on the other end. There are the four tie bolts that hold the motor together.
It does look like the grill has seen some years in the weather. Hard to tell if you need to replace it until you take it apart and see how much damage there is. Maybe clean it up and paint would get you going.
If you can get those rusted nuts off I think you will find those bolts are long and go all the way thru the motor. Chances are they will break trying to get them out and you would need a new bolt kit. It may be part of the grill replacement kit.
Depending on the hole size you could maybe tap those holes and get that to work. Doesn’t seem like the way it should be done though.
Do the two holes on the shaft end of the new motor go all the way thru the frame? Are they on the correct bolt circle diameter at the grill bolts?
Do the wires and connectors match up with what the old motor has?
I agree, but it does appear that's what was they were thinking.
I doubt they used some sort of self tapping screws but who knows.
We may have some folks here with AC experience and I hope they come into the discussion and tell us what we don't know.
I understand the reluctance on tapping holes if it is something you haven't done much. If you have a way of measuring the hole size I can give you an idea of what size tap you would need, and maybe they missed the holes when building the motor. You could then compare it with the size bolts you have in the old setup.
I would likely start tearing the old setup apart and see what you have. I'm assuming the motor is shot anyway and it has to come off.
Again I would take the old one apart before I did anything. If you need a new grill you will want to make sure that is also the same or a match for the new motor.
Yes if you decide tapping the holes for bolts is what you want to do and the holes that are there are not a size that works then you could drill them slightly larger for the bolts that would fit the grill to be the proper tap drill size.