another GT40P header ?

burntfish · Aug 9, 2012

I have been reading old posts for 2 hours and I'm lost. I thought I read somewhere about using headman headers on GT40P heads. I was thinking someone used the 88400's on a GT40P setup. I know there are headers from several Bronco company's that fit, but are all real expensive. Need cheap as possible.

broncnaz · Aug 9, 2012

Most standard bronco headers will fit but you may need to clearance a few of the tubes with a hammer and or run shorty sparkplugs. Usually the mustang type headers will require other modifications to clear the frame on the pass side so you can hook up the exhuast pipe

BroncoBrandon · Aug 9, 2012

I'm finishing up my engine swap right now and like BroncnAZ mentioned you wont find a cheap set of headers unless you are willing to modify them for clearance.

I have a set of Doug Thorley headers that I may need to clearance so that I can get the spark plug boot on it. Also will Have to modify a socket to get the spark plug in/out unless I want to pull the header each time they need to be replaced.

I think that all the little things will be worth it in the long run though (I hope)

burntfish · Aug 9, 2012

I am willing to modify them as needed. Just trying to remember if the headman 88400 fit with after modifications.

u10072 · Aug 9, 2012

If you want cheap --get a shorty 89-93 mustang header-- the #7 plug area will need to be clearanced-- heat up the tube and find about a 2" piece of pretty solid steel and whack it for clearance-- just mark the header where the plug wire will touch before hand-- I would say a good half inch is what you need so you arent killing plug wires-- you are going to have to run really good plug wires and heat boots as an FYI. Thats the very easiest method and no welding.

burntfish · Aug 9, 2012

Will the mustang headers have frame rail issues.

BroncoBrandon · Aug 9, 2012

burntfish said:
Will the mustang headers have frame rail issues.

Shouldn't be an issue. If I remember correctly the frame rails are a bit wider on a bronco.

Anyone know for sure?

pullnpray · Aug 9, 2012

Dont the p heads have a weird fitment issue i thought i read that it was something to do with the angle of the plug.. i could be wrong im like you been reading and im confused

broncnaz · Aug 10, 2012

Almost all the later model mustang headers will have clearance issues on the passenger side as the header dumps directly into the frame rail. Not sure about the early ones.

Yes the P heads have a different angle on the spark plugs so specail headers are built for them the go around is to dent standard headers for clearance. probably not the best meathod but it is the cheapest. probably wont lose much of anything in the way of power since bronco engines are not high RPM engines anyways just dont expect any real gains either.

Ourobos · Aug 10, 2012

The GT40P is the best iron head ford has made.. I'd expect quite a bit of a gain over the stock 302 heads..

broncnaz · Aug 10, 2012

No real big gain maybe 20 hp if your lucky. Probably not notcieable unless your racing or dyno testing. But I guess they can be found and swapped on for fairly cheap so the cost vs benefit can be there.

Hozr · Aug 11, 2012

You'll get better tourque with the P heads but not much HP.

The mustang headers require extensive modifiction to the passenger side. The stock Bronco header dumps straight back where as the mustang header dumps down. By the time you modify it you will lose any gains from the head swap.

The spark plug angle of the P also means you have to clearance individual tubes for plugs, performance loss again.

So, if you want to save a buck on headers to waste money on losing performance go for it!

ETA: Im running P heads with the Sanderson headers. Perfect fit
P heads need P headers, plain and simple. They will run you about $300. The short cuts arent worth it otherwise.

BroncoBrandon · Aug 11, 2012

A little late with the response but oh well. These are the P heads with Thorley exhaust headers designed to fit a EB with an older 302.

This is the drivers side and you can see that the front spark plug has some clearance issues.

This is the passenger side and there are no clearance issues that I have seen yet.

burntfish · Aug 11, 2012

Headman

sanderson
These are the headman 88400's. From what I can tell they are the same as the sanderson headers.

u10072 · Aug 11, 2012

Its the #7 cylinder (cylinders 5-8 are on the driver side) you are worried about typically-- those Headman can be made to work almost positive but I wouldn't say they fit guaranteed. I am probably going to buy a pair of the Sanderson-- but I want a roundtrip shipping guarantee if they dont fit the heads correctly-- as in dont burn up the plug wires on the driver side and they fit the frame rail. If they do I am going to be super happy!

rojo23 · Feb 5, 2013

so you basically need to dent one of the tubes so that the plug wire does not hit the header? Does any of the bronco venders sell the gt40p headers?

BroncoBrandon · Feb 5, 2013

Yes, But I cant seem to remember who sells them. I want to say BC Bronco but Im not 100% on that

WyleCoyote · Feb 5, 2013

Bronco Hut sells headers that are supposed to work perfectly with GT40P headers

BroncoBrandon · Feb 5, 2013

WyleCoyote said:
Bronco Hut sells headers that are supposed to work perfectly with GT40P headers

http://www.broncohut.com/Home/tabid/39/ProductID/1218/Default.aspx

rojo23 · Feb 5, 2013

looks like that is the only fits all header. they claim that there are not fitment issues. most of the other research I have done said that there is at least 1 plug that interferes with the tubes. Has only one else used just the plain mustang shorties? they seem a lot easier to find, and priced a little lower.

another GT40P header ?

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