Will a 5.4 3V with harness bolt into my '99 mustang and with my 4.6 intake and the other regular swap necessities work? THX, Mark

 

No it will not. There are no adapter plates available to adapt 3V heads to PI intake manifold. If you are getting a good deal on the 3V engine, it is possible to use most of it. You can use the block with your PI 2V heads, then you can use adapter plates for the intake. You will also need a 2V front timing cover.

 

THX, back to looking!

 

just re use your wiring harness. you just have to lengthen some wires. and get the 4.6 much better intake.