GT-40p heads

yo yo-
I've got a chance to pick up some gt-40p heads from my pal who never used them. ultimately i'm doing afr, but that'll be when my pockets are a bit deeper. In the mean time they are a clear advantage over my stock heads, i've completely redesigned my intake, minus the manifolds and i was going to put that money to remodeling the exhaust system.
I know the gt40p heads are pretty good, but are they worth getting before i rebuild the exhaust? Also, tell me what you guys know about the gt40ps. I know they out flow, and are restricted by lift but I’m sure you guys know much more.

GT40P's will be a better then the stock heads. The thing about the P heads though is the exhaust side still flows crappy compared to the intake side, still will make more power on average then stock heads. The smaller combustion chamber of 60cc vs. the 61.5cc stock, will give you a higher compression, 9.21:1 vs. 9.1 stock. This will result in a slightly better low end pull. There are a few down sides to the P heads now. 1, you need to buy new headers, cause the spark plug angle won't allow for direct replacement headers. 2, the thermactor holes found on the back of stock heads used for emissions, do not exist on GT40P's. They must be drilled and hooked up to the smog pump. If your lucky you live in one of the states that doesn't have strict emissions laws and you can get away with it. What is the price this guy is selling the heads for anyway? My guess, you might gain around 30HP buy installing the P heads depending on you other mods, exhaust etc.
Here's some flow data I had.
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Stock Heads
Port Configuration I/E
Valve size (I) 1.78 (E) 1.45
Lift
0.100 59/42
0.200 114/78
0.300 144/105
0.400 156/115
0.500 156/116
0.600 156/117
0.700 n/a

GT40P heads
Port Configuration I/E
Valve size (I) 1.84 (E) 1.46
Lift
0.100 61/52
0.200 128/90
0.300 169/123
0.400 195/135
0.500 196/139
0.600 193/142
0.700 n/a

he was going to hook it up at 300 bucks, which seemed pretty fair. if it's going to cause me to go through the hastle of milling, i'll just wait for the afr fairy to visit me. I was kind of hoping to just slap them on there and be done with it.

While i have your attention how long does it take to pull out your engine?

Great head/great price.I would think about buying and porting/polishing/redo heavy duty Ford racing springs with TI retainers as well as 3 way valve cut probably 15/30/45.I would port match the heads to the intake that should also be ported and polished and they can be done by hand with the proper tools,and thats if you are mechnically inclined.
If not contact me [email protected] and I will provide you with free tech service and advice.Good Luck,Dave Smilovic
PS;My partner in Canada does 5-700 sets of heads a month so were extremly well versed and our Canadian Ford shop Techs are always going to school at least 30 days per year per tech,and that is why we build the worlds fastest modular motors on earth.So you can look forward with complete confidense that we will get you some heads that will rock your world!!!!!!!!!!!!!!! BIG TIME!!!!!!!!!!!!!!!!!!!,Dave Smilovic
PS you can reach Sean at seanhylandmotorsport.com.Tell them Dave S. from AZ. sent you and you will get a discount.I dont take referal fees I feel there not ethical but he will pass any savings direct to you as it should be.
Brace yourself he's not as expensive as Saleen and SHM/Saleen/Steeda and rouch are the only 4 I love but from a performance view point going just to find an every day driver with no wings and aliminized junk we use only the finest grade everything.Good Luck,Dave Smilovic