Build Recommendations

[N8Dogg98]

Hey guys I think I am going to finally do some serious mods the stang this spring and was hoping to have some input.

I'd like to either buy a used set of PI heads or have mine ported. I'll also be buying a set of stage II NA cams from Hitech Motorsports. Hitech is about 20 minutes from my house, so I'll probably have them tune it too.

I'm not sure what to do about the heads yet. The PI heads would raise my compression ratio and also improve air flow which is sweet, but porting mine would probably offer a little better air flow and I've heard ported NPI heads are better than PI heads for a NA car. If I buy used PI heads I run the risk of picking up a set of heads that are warped and need serious machine work before bolting on to my car, but cleaning, porting, and installing new valve guides and seals on my current heads is probably going to cost around 1000. What do you guys think is my best bet? Thanks for the help! :SNSign:

 

[Gearbanger 101]

Hey guys I think I am going to finally do some serious mods the stang this spring and was hoping to have some input.

I'd like to either buy a used set of PI heads or have mine ported. I'll also be buying a set of stage II NA cams from Hitech Motorsports. Hitech is about 20 minutes from my house, so I'll probably have them tune it too.

I'm not sure what to do about the heads yet. The PI heads would raise my compression ratio and also improve air flow which is sweet, but porting mine would probably offer a little better air flow and I've heard ported NPI heads are better than PI heads for a NA car. If I buy used PI heads I run the risk of picking up a set of heads that are warped and need serious machine work before bolting on to my car, but cleaning, porting, and installing new valve guides and seals on my current heads is probably going to cost around 1000. What do you guys think is my best bet? Thanks for the help! :SNSign:

You can buy brand new PI heads, complete with valve train and cams for about $800 foir the pair. Unless you can rebuild and port your current castings for less than that, the choice should be obvious. In most cases, ported stock NPI heads are only really worth the money if you can do it yourself.

 

[N8Dogg98]

Do you think it's worth buying a used set of PI heads? I can probably get a pair of used PI heads for around $200 to $400.

 

[Gearbanger 101]

The set I’ve got on my engine were used. But I performed all of the work necessary to them myself….so it basically only cost me the price of the heads and new valve seals. Also, keep in mind, when I bought them New PI heads were still somewhere up into the $2,000 range and not $800 like they are now.

Modular heads aren't famous for warpage, so I wouldn't hold that as my primary concerned. As long as there are no deep nick’s on the head surface itself around the combustion chamber or the water passages, you're probably good to go. Also, unless the heads you pick up (PI or Non PI) have a lot of mileage on them, I doubt they need guides either. A fresh valve job would probably be the biggest expense. A good valve job can run you a couple hundred bucks though, so I would insist on seeing them apart before plunking down any cash. Deep pits in the valve face and signs of leakage around the seat on the head itself are what you’re looking for. Assuming they’re in good shape, a quick relap and a set of new rubber seals (cheap insurance) to them and you're probably good for another 100,000K

Keep in mind though.....If you factor in the cost of a set of used heads at $400, then the cost of the valve job at $200-250.....then seals, reassembly, etc.....you’ll probably only save about $100 over the cost of buying them brand new. In which case you know they’re going to be virgin and they’re not going to have any issues with them.

Also, keep in mind if used is what you decide, you'll want to stick Romeo castings (2001-2004). Earlier PI heads were Windsor based 1999-2000 and require the use of Windsor valve covers as well. So if they're early and don't come with valve covers, factor that into the cost of your swap as well.

 

[CobraRed_96_GT]

Buying new PI heads means you pick up 15cfm intake and some compression. Buying used ones does the same but they are used and who knows what kind of condition they are in (my first set would have needed new guides and a decking). If your going to use used heads might as well use your NPI and have them ported. Or buy someone else's and have a shop port them and go over them. That's a good 60 cfm intake 40 exhaust and you can keep your current compression for future boost or just for running regular gas.
If you don't want the down time, i have a set of NPI heads from my car sitting in boxes.

 

[96SCstang]

i have a set of NPI heads from my car sitting in boxes.

pm me cobrared_96_gt. let me know what you want for those heads. thx

 

[N8Dogg98]

If I were to use my NPI's, would I be able to use the Hitech stage II NA cams? What additional parts would be needed on my NPI heads to accept this cam (I thought I heard there was a valve lift limit on NPI's). IIRC the lift is .550 on the intake side and .500 on the exhaust.

Also, can the intake side of the NPI heads be port matched to the PI intake?

 

[CobraRed_96_GT]

You can port match a PI intake just fine. You can't run .550 or something close to that lift on NPI heads, the spring size doesn't accommodate it, only if you ground down the spring landing or something. At least this is what i understand - i'm a PI guy now

 

[N8Dogg98]

Good stuff, thanks for the info