Wheel/Rim Question

I have a general question that maybe everyone can help me out with.

In my ongoing search for rear tires, I have found a set of 15.5-38 firestones, mounted on "double bevel" rims. I have a '49 M, and I have no idea what kind of rims are technically on it.

So, two questions.

1. What kind of rims are supposed to be on an M?
2. Will these other rims fit? Or should I just forget the whole idea.

Thanks in advance.

~Bug

I see after some searching (Yeah, I should have done that first) that apparently the wheel centers are different from the Drop Center (or Deep Well) type rim to the double bevel type.

I could still buy the tires and rims, dismount the tires and put them on the rims I have now, then sell the rims to someone else, but I honestly dont know if its worth the hassle... The tires are only about 50%, and for what I would pay in the mounting/dismounting, I might just be better off buying a new set of rubber and paying to mount them once.

Thanks for the input everyone!

~Bug

I had thought about buying another set of centers, but I really would then rather just spend that money on a new set of rubber rather than a used set.

As far as the tire size is concerned, it has 15.5x38" tires on it right now, on the stock rims (which I think are 11" or 12"). The engine was rebuilt about 500 hours ago with the oversized pistons and sleeves to make it equivalent to a Super M. The previous owner never had a problem with it turing the bigger rubber, but I havent had a chance to see what it will do.

But I guess I'm a little worried about putting that size tire on the stock rim, so I dont mind moving down a size to a 14.9 or a 13.6 if the opportunity presents itself.

Thanks again for the replies.

~Bug