P.I. Heads vs. Aftermarket heads

What are your hp goals?

 

A stage 3 port on a set of P.I. heads will flow the same as a set a TFS heads but by the time you do the port and upgrade the springs the price difference is only like $200 off the top of my head and the TFS has some rebuilding options that factory cast don't, also if you goals change down the road the TFS heads can still be ported to flow even better.

 

I bought a set of pi's from a junkyard and bought a set of carbide bits and just did some work on them myself. I am sure they aren't perfect. But both machine shops I took them to said they were decent. I did built bottom end, .020 over, wap block, cams and eddy jr intake. It runs good, but it is eating me up in the back of my head that I didn't go with some professionally built heads. And like torch said, all said and done you are in the same ball park anyway.

 

Some people say just turbo the car with stock heads and turbo cams and call it a day, so its all depends on what you want to do.

 

A set of stock heads with a few tricked out port touching (in no way you would think of a porting scenario) can handle some serious compresion, but im a n/a guy and care less about forced induction. torch318 pretty much sums it up if your wanting 500+.

 

You're not going to get a stage three ported head for $1200
http://www.modularheadshop.com/CylinderHeads/2VPI.aspx

A m112 is not a direct swap as the four valve heads are different. You will need a conversion kit from tork tech along with other parts.
http://www.allfordmustangs.com/for...wer-2-valve-4-valve-supercharger-swap-gt.html

 

The port cost money then you're gonna want to replace everything in the head. Valve seats seals guides springs retainers cams lifters and followers before you know it BOOM another 1500 bucks.

 

What do you want to spend on this build? We would be able to tell you what your budget will get you and what you could expect for power. Are you going to do the work yourself?

 

remember the old saying " gotta" -pay to play, first off the only aftermarket casting for modular 4.6's are trickflow heads, anything else is just a factory ported casting pi or non pi. its same with my year 5.0 pushrods, everybody wants to cut corners save money and go with factory ported gt40 heads, but by the time you do valve jobs, springs, retainers, rockers, port work shipping back and forth if you have to pay to ship them out your talking $1,000. you could of bought aluminum head that flow same or better unported and still room to port. same goes with pi heads, might aswell find a cheap pair of pi heads to do pi swap and port them if not just spend a little more and get a set of trickflow heads. hands down fastest 2 valve cars I see are either turbo or have trickflow heads. or both.

that being said I stand by trickflow I run them on my pushrod 95 5.0 and love them trickflow all day.

I would say trickflows if you want to keep it all motor, most of the fastest n/a 2 valve cars or dynos I'v seen have been trickflow headed combos/ and or 5.1 stroker / cars.

and fastest power adder 2 valve cars ive seen have been turbo cars or ones with the torktech kits with 03 cobra blower twin screw kb / whipple or eaton setups with forged motors.


But hands down 2 of most impressive 2 valve ive ever seen was a car that had a cobra block , trickflow heads forged 5.1 motor with turbo kit, thing made 650rwhp on low boost pump gas had over 800 on race.

and

saw a 8 sec 2 valve car was a 99+ gt with same setup 5.1 stroker forged trickflow heads a huge turbo and 25-30psi thing was running 8.80's in the 1/4 .

 

In most builds the supporting mods cost more than the engine build. Generally you can figure $40-$60 per hp over stock for final cost unless your very creative with part selections and run across some good deals.

 

this is true. but sounds like your not worry about budget and 450-500hp, so if your looking for 600+ I WOULD SAY SPEND THE 2K BUY THE TRICKFLOW HEADS. LOL

 

I have as much money into my fasteners as I do into my lower end on one of my builds.... ARP shit adds up quick.