I know this question gets asked a lot and I did several searches but just want to clarify a few things. I want to put in a 351 in place of my dogged 302. I have a 95 with mass air. Will my mass air and upper intake work with the 351? Do I need a new computer? If I am putting on headers what exhaust parts from the 351 will I need? Will all the pulleys and accessories bolt up? Thanks!

 

Okay, since no one else is touching this one I will give it a shot. According to the Ford parts, there are different computers for the two engines (302/351) because they are a different firing orders. You can get a used computer to match your motor from a salvage yard. I know that the 351 had mass air in 1996 and I think it was on the automatics in 1995. The upper intake will not work. The intakes are the two pieces and are totally different. On the 302 the lower part of the intake has squarish holes in it, while the 351 has rectangluar holes. The lower part also is wider to fit the 351 because of the heads being pushed out about 1" wider than the 302. The upper intakes match the lower intakes in the shape of the holes. As far as the pulleys and accessories... the A/C compressor, Power steering pump, air pump, and alternator are all the same. The belt tensioner is in a different location. The brackets that hold the pulleys are the same also, the difference on the A/C-Power Steering bracket, is that there are different holes to mount the bracket to the motor. They are already pre-drilled so it should work just fine. I used all of the accessories and brackets from a 302 on my 351. The exhaust is a different story. I have heard conficting stories on the y-pipe being different. The heads are farther apart so the y-pipe on the 351 should be wider. Makes sense to me. I bought a new y-pipe at a local part store for under $80.

Hopefully this clarifies things for you.

 

Thanks for all the information swirk. I'm thinking at this point the easiest way to do this thing is to buy a wrecked truck with everything I need and go from there. Thanks for your help.