I'm new to the board so I am sure this question has been asked and answered many times but I would like to know. I have a 90 f25o 4x4 with a 460 and a zf 5 speed and I acquired another 90 f250 4x4 with a 351 I don't know if it is a Windsor or m and it has a 5 speed I don't know if it is a zf, what I want to know is are these two transmissions interchangeable? Thanks for the info.

 

No they are not. The trans in the 351 should be a ZF but the bellhousing pattern is different from the 460.

 

Should be a Windsor