I just did the swap. The donor car was an '81 264 (PRV). Everything is indentical except for the size of the rear axle "nut" (or whatever that is at the ends of the rear axle). I can't put the 164 steel wheels on with the hubcap holder in place: The axle nut is too big, and there's not enough room. (The hubcap holder is a strange-looking steel bracket that fits in the center of the wheel, and that huge phillips-head screw on the hubcap screws into it.)

I thought I'd check here to see if someone has done this before and come up with a solution. I'm thinking of making my own bracket that screws onto the outside of the wheel under the hubcap.

-Adam