Gt40 p heads

GT Rob · Sep 21, 2014

Need your guys opinion I have a chance to buy a set of gt40p heads today for 350 dollars it comes with headers the guy said there ready to bolt on all it needs is to have them shaved

RichV · Sep 21, 2014

I'm on the fence. Are the headers GT40p headers? Or just a set that work? Remember the SNs have different headers than the Foxes. Not just the emissions port.

The heads make great power, no disputing that. But my experience is you'll burn up plug wires. May not be a huge deal on a street car, but I lost races due to it. So I'm going with standard GT40s, sell the 40Ps.

DavidBoren · Sep 22, 2014

First off, are the headers specific to the "P" heads and your vehicle? If not, they aren't much of a motivator.

Second, what are your intentions with adding new heads? Are you staying naturally aspirated with this engine? Is this just a street car? If you have plans to add boost, then don't waste your money on new heads... just add the vortech and be done.

On a naturally aspirated engine, with the proper headers, and a little higher compression ratio due to shaving the heads, the GT40P heads are pretty solid. If you score them for cheap and have a little budget money left over, getting new valve springs and 1.7 rockers would give you an excellent combination.

GT Rob · Sep 22, 2014

Not boosting anytime soon. Did a compression test and we figured that I might have a valve that is stuck so instead of putting stock heads back on I thought I would do heads cam and intake

Addermk2 · Sep 22, 2014

Its your money... personally, I wouldn't ever run a stock head again.

Still think you should just pull a whole Exploder engine from the scrap yard, change the cam and drop it in.

GT Rob · Sep 22, 2014

What year exploder and is it a direct fit

Addermk2 · Sep 22, 2014

96+, If you get a 97 or newer, they will likely already be GT40P heads, in which case you are advised to buy the MAC "P" Shorties.

No it's not a direct fit. You will need to remove most everything from the long block, and swap over your accessories and such. The GT40 intake on the explorer will also require an adapter elbow to mount your throttle body.

GT Rob · Sep 23, 2014

I have a gt40 intake and the elbow also

Addermk2 · Sep 23, 2014

Irrelevant

CC'S95GT · Sep 23, 2014

FRPP and MAC make P specific headers. Also BBk shorties can be used but there's a slight clearance problem with 1 tube and that can be fixed with a 90* boot and some heat shielding.
IMO $350 isn't a bad price if they were ready to bolt on but since they need to be shaved too (which means disassembly, cleaning and reassembly of the head).

Z06killinsbf · Sep 23, 2014

Around here you can get complete explorer motors for that much! Sell the intake that comes on it and some of the other pieces and recoup some investment. Idea?

95opal · Sep 23, 2014

RichV said:
Remember the SNs have different headers than the Foxes. Not just the emissions port
.

Fox shorties an sn headers are identical except for the egr bung.

Don't waist your time on the p heads you can find a used set of aluminum heads for the amount of money your going to dump on the heads and shaving them along with p specific headers. There really not worth it IMO

DavidBoren · Sep 23, 2014

I have been giving this a little thought, and after a very quick search I found an assembled set of aluminum heads on ebay for $700. How good they really are is still questionable, but you have options for valve springs and the valves are big boy 2.02/1.60's with 180cc intake runners and 60cc combustion chambers. Link:
http://m.ebay.com/itm/320898688214?cmd=VIDESC&gxo=true

How much does it cost to get a set of "P" heads decked? If he isn't thinking about boost any time soon, then a factory set of Gt40 heads might be what he is looking for. $700 might be out of the budget. Those cheap aluminum heads with huge intake runners would require a custom, or at least carefully selected, cam to perform well on an otherwise stock engine.

I would seriously consider what it will cost to refresh the "P" heads.

If you can swing for aluminum heads, definitely go with them. I am a huge fan of big heads and a well-matched small(ish) cam. And aluminum heads have the added benefit of reducing weight. We all know that less weight is the same as more power.

RichV · Sep 23, 2014

95opal said:
Fox shorties an sn headers are identical except for the egr bung.

I disagree there. Leaky header collectors every time in my case.

95opal · Sep 23, 2014

RichV said:
I disagree there. Leaky header collectors every time in my case.

Put a set of each next to each other there identical. Long tubes are another story but the shorties are identical
Ran fox shorties for years never a probleem

Evilgt · Sep 23, 2014

Why do the heads need shaved? Warped? Where they on a car that was over heated 4 times a day?

Around here you can j/y those heads for 75 each.

I like the GT40s. Made 440/520 to the wheels on a little T44 turbo at 8lbs of boost with a E cam and performer 5.0 intake.

kyle

RichV · Sep 23, 2014

95opal said:
Put a set of each next to each other there identical. Long tubes are another story but the shorties are identical
Ran fox shorties for years never a probleem

Dunno, I have a set of BBK Fox shortys and MAC SN shortys. 2 different h-pipes, the MACs were good but wouldn't work with GT40p heads. BBKs leaked with both h-pipes, both sides. Weird coincidence.