We have a 1995 F-250 w/ 5.8L-351 4x4 can we take off a Cat from another truck a 1990 F-250 with a 5.0L-302 will they be compatible? It is going to need to pass the state of N.H. inspection.
Any advice and suggestion is appreciated.
Thank you,

 

The cat/Y-pipe would be compatable if they were from the same engine but that one won't be a direct bolt-on since the 5.8 is taller and wider than the 5.0. You can make it work pretty easily though, just cut the pipe that goes under the motor and widen it a little.

 

Like he said there will be issues due to size difference but both are obd1 so the cat will work.