Issue with Tires

Hey all, first time poster here. I recently bought a 1990 4runner and am keen to swap out the tires asap. It came with pretty new studded winters that are sized 235/75R15. I just bought second hand summers on rims that are sized 31X10.50R15.Itt was my understanding that these are the same size and can be easily swapped out. When I went to swap these for new rims they seemed exactly the same but they are about 2mm off clearing the axle head (bit in the middle not 100% sure what it's called). The bolts look perfectly lined up but the inner circle is just slightly too small. The full diameter of these two are the same, I guess I just don't get how I could have seen the difference in the two rims. I can see visually that the gap between the bolts and the inner rim is larger on the new rims than the new. My question is, can I somehow file down this gap or something to get them to fit right. I know I can always go to a mechanic and get the tires swapped to my current rims. But I would really like to avoid spending anything at this time.
If anyone has any ideas or help that would be great. Thanks all I'm glad to be part of this community!

 

Your donor tire rims don’t look like Toyota rims, personally I wouldn’t use them.
31” tires are larger than 235 tires.
30” x 9.50 tires are comparable to 235.
I had 31” tires on at one time but the 22re didn’t like it.
I have 30” tires on now and Goldie is much happier and they are more robust than 235.
Trivia:
Back in 1990 if your 4R came with the OEM optional 31” tires you got 4.56 gears rather than 4.10 gears/225 tires that regular models got.

 

Your rims are not the correct offset for the vehicle. Mine originally came with 225's and I now have 31's. I went with 15x8's, not sure of the offset, but they put the tires out from the side of the vehicle a little bit. No rubbing at all. If you can find rims with the correct offset, the 31's will have no issue fitting.

 

The rims shown on his 4R in the 1st photo are OEM steel rims, same as mine. They were originally silver from the factory but that paint tends to flake off, hence the repaint. I think the marks you see on the tire are curb rash. He is having a center of rim bore fitting problem, not a tire clearance issue.

 

I see what you are saying. It is possible that the rims he got came off a 2wd model. Those will not fit a 4wd model. The front hubs of a 4wd are a bit bigger than the 2wd model.