318 and 904 swap question

I have a question for you guys. My 74 swinger is a 318(needs a rebuild bad) with a 904 transmission(needs rebuilt as well)and a 8.25 rear end.

The donor car I picked up has a strong 318 in it now with a 904(shifts good) hooked up to a 7.25 rear end. Here is my question for you.

I am wanting to move the motor and trans from the donor car to mine until I can get mine rebuilt.

Will I run into problems with the swap because mine has the 8.25 rear end and the donor car has a 7.25?

Thanks for any advice!