Diff in GT40 and GT40p heads
- Thread starter Stevejr
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KamiKaziDK
Member
you need special headers for the P's cause the spark plug angle....get regular gt40s unless you've done nothing to your exhaust and plan on getting headers in the future....then it's whatever you get a better deal on...usually Ps.
I also have a question about these heads if someone can help...I know that the P heads are not drilled on the back for smog but it seems that the standard gt40 are not all drilled either. Which ones are drilled and why? I want to run them on my buget build but can't seem to find any with the smog ports and I have to run them for emissions testing. Sorry if I jacked this thread, hope you guys can help.
blksn955.o
Founding Member
My regular gt40 heads have the ports in the back. From what I read years ago the P's can not be ported as much due to the water jacket being closer/over the runner.
Stock for stock the p's should and seem to make more power...not much on avg. but more. If you find both sets for the same price get the P's. However, going with non p's will not be that big of an issue.
Stock for stock the p's should and seem to make more power...not much on avg. but more. If you find both sets for the same price get the P's. However, going with non p's will not be that big of an issue.
KamiKaziDK
Member
MORDENENOUGH.....they should both have smog on them, these heads are all from 93 and newer vehicles.
MORDENENOUGH is right about the smog ports on the gt40's,i cant say for sure about the gt40p's though.
the heads on the left are from a 97 explorer.the red arrows point to where the smog tube would attach.note the small hole next to the large hole with the threaded plug.its the same on the other side.
the head on the right is from a later model Mountaineer.this is the drivers side head with the rear of the head facing us.blue arrow-its just a threaded hole,it just stops,so it dont need a plug.also has no small threaded hole to attach the smog tube.its the same on the other side of the head.
(sorry,this is the best pic i could find.i know it's kinda hard to see,and yes they are all gt40 heads,not p's)
View attachment 275110
heres a pic of the explorer heads with the plugs removed.(yellow arrow)
View attachment 275112
on a side note.the upper and lower intake from the explorer was unpainted,cleaned up pretty easily.
but,the upper and lower from the mountaineer had somekind of REALLY tough paint on it,took me all day today and many coats of aircraft stripper to get it off.
i'm kinda loopy from all the fumes
the heads on the left are from a 97 explorer.the red arrows point to where the smog tube would attach.note the small hole next to the large hole with the threaded plug.its the same on the other side.
the head on the right is from a later model Mountaineer.this is the drivers side head with the rear of the head facing us.blue arrow-its just a threaded hole,it just stops,so it dont need a plug.also has no small threaded hole to attach the smog tube.its the same on the other side of the head.
(sorry,this is the best pic i could find.i know it's kinda hard to see,and yes they are all gt40 heads,not p's)
View attachment 275110
heres a pic of the explorer heads with the plugs removed.(yellow arrow)
View attachment 275112
on a side note.the upper and lower intake from the explorer was unpainted,cleaned up pretty easily.
but,the upper and lower from the mountaineer had somekind of REALLY tough paint on it,took me all day today and many coats of aircraft stripper to get it off.
i'm kinda loopy from all the fumes
GTA_V6_Mustang
Active Member
Just get the ones you have P&P.
The good thing about the P's is hands down they start flowing a greater amount of CFM at lower valve lift. And theres ways around the water jacket thing, trust me we got around it on my heads
. I like the P heads but if you have the regular 40's already its not a big deal. And the way to tell the regular 40's from the P's is the P's will have a P, lol. And on the ends of the heads they will have 4 ribs instead of 3.