I'm looking to put a set of PI heads on my 97 4wd reg cab f-150 4.6L what do i need to look for/what years/models will fit/does the cab absolutely have to come off for the swap/ and what other components should i change while im in there? thanks

 

I would pass on the PI heads and have a set of NPI ported and polished. The results will be about the same with NPI heads, but you will need only the heads.
I swapped heads with the engine still in, and I don't suggest doing that way, pull the engine

 

What he said^

A good pnp job on NPI heads will outdo PI heads...

You already have the NPI heads besides, but even if you didnt want to take them off and have downtime on your truck while your heads are pnp'd, you can buy a set of NPI heads for pretty much nothing.

 

I gained 105hp at 4000rpm with pi heads, and comp cams#102500. I did the swap with the engine in the truck in 1 day. not that bad. I have a 2 page write up if you want it. Email me and ill send it to anyone who wants it

 

thanks for the info about the PNP on the NPI heads, i may take that route. downtime on the truck isnt an issue i have a couple other vehicles i can drive. should i do a cam swap or injectors or tb or anything while im ripping it all apart to see some better gains or would just a PNP on the heads be efficient for now?

 

different cams will add to the pnp gains especially if you go oversized.

 

Used PI heads are everywhere, go over to some Mustang forums, you'll find them. PI heads are PI heads.

www.corral.net
www.modulardepot.com

Just to name a few.