Will my 97 GT40 manifolds fit GT40P heads?

[Handegard]

I've googled and all I come up with are GT40 vs GT40P as it pertains to upgrading Mustangs or other 302s....

I'm looking for a set of heads. If all else bolts up, I'd rather have GT40P heads as I understand. I get that the factory manifolds from Mustangs won't clear the spark plugs, but I want to know if the factory Explorer tubular headers will?

I broke a intake manifold bolt in my '97 EB, then broke a easy out. First machine shop said he couldn't get it out, and referred me to a shop with a special machine that could. They said $200 per bolt, and recommended I get heads.

Since I have GT40 (3bar) heads, can I replace them with a older casting (lets say I have a complete rebuilt set of C9 or E7 heads)

I'm sorry if these sound like dumb questions, but I'm not able to run out and look at my heads, or my explorer, or my other heads, and they are all currently far away from me in storage, or at the machine shop, or my fathers....

 

[section525]

I'm running GT40 upper and lower intake manifolds on the GT40P heads.

I wouldnt replace them with anything worse than the stock GT40s though.

 

[Handegard]

Ahh, how could I have failed so miserably...!

I meant the Exhaust manifolds. I know the top end will fit, and the headers will bolt up, but I've been told the spark plug location makes most factory manifolds not clear. However, this is all talk about mustangs...

As far as the old heads, I have no concern at all for power, zero, today. Right now, I need to get my X back on the road. I was planning to rebuild a engine this summer to swap in, but the budget doesn't exist for that now, and if I could just get it on the road with some older castings I have now, I'd be more than happy.

I'm buying another '96 5.0 hopefully, that I'll tear the motor out of, rebuild as I want, then swap into my '97. But that won't be for months.

 

[CDW6212R]

For that 97 GT40 truck, you should stick with GT40 heads. Skip the GT40P heads, those do require GT40P headers. You don't want to swap to those and be buying heads and exhaust manifolds just to get the truck running. Find the GT40 heads, they are easily found on eBay and salvage yards from 96-97.5 Explorer 302's.

If you build another engine, then that one will have to match too. So stick with the GT40 heads for now, that lets you use the existing headers, or the two other aftermarket no so great choices also. But at least you can swap to a much better head if you want to, like a TFS Twisted Wedge head(different pistons required). Those are great heads, worth buying even used to rebuild with.

I would never spend much on GT40 heads, just as little as possible to get them usable. The older C9 or E7 heads should all be scrapped, those are even worse than GT40 heads. Just my 2 cents.

 

[Handegard]

Can anyone answer this-

What is the difference between the two, fitment wise? All I can find is plug angle. Does the intake bolt pattern change? Or the exhaust pattern?

I've looked at dozens of photos online, and I truly think my exhaust manifolds will fit. Unless someone can say "no, the bolt pattern is entirely different"

I say this knowing that the exhaust manifolds I have are not the factory ones, and I know that they did not fit correctly on my heads. My first assignment at the shop I worked in for a few years was a tranny swap and a new set of exhaust manifolds for (what came to be) my Explorer (purchased from a customer)

I'm thinking I have GT40P manifolds, and thats why I had fitment issues the first time.

This is what I have one mine-

Complete with the capped and unused EGR bung on the top.

Maybe I have it all backwards, but as I understood, spark plug clearance is the issue, and in all the pics I found of Explorer 5.0 manifolds it looks like there are two styles, cast iron and tubular, and the cast iron manifolds have a wider port (look to flow better) and the tubular ones are bent inwards for bolt clearance, and look like they'd have more room for the spark plugs than the cast iron.


Please understand that I'm not some stubborn person who isn't going to listen to anything you say. I've been a auto tech for 5 years professionally, and I've rebuilt my fair share of motors, transmissions, and anything else. I have experience and tools, I just don't have a set of heads side by side to compare too. So I ask alot of questions, but it's not pie-in-the-sky stuff, I'm just trying to weed out solid answers. If something can't be done, I won't attempt it, I just want to make sure first...

I am planning a bit better than a stock rebuild. I was hoping to get some Torque Monster Headers, a camshaft, and probably a K&N FIPK if they make one or just a K&N cone. Nothing wild, but if the GT40P heads are preferred, I'd rather end up with a pair of them now than buy more GT40 castings. Plus, it looks like I can get a set of GT40P heads cheaper than GT40 heads, and the cost of the manifolds is about the same as the difference in price.

 

[CDW6212R]

Those are going to be GT40P headers, if they have the EGR bung in them.

The plug clearance is the issue, as the bolt patterns are the same. I gather from others that you can use one header on both heads, but not the other type of header on both heads. I'm not sure which it is, in one case the plug wires just end up right on the manifolds and can work. The other way the wires will not go on all of the plugs.

If those are GT40P headers than you have a super tight fit at the plugs, it should be obvious.

 

[Handegard]

EGR bung equals GT40P manifolds? It's that simple eh...

I managed to get the easy-out out of the head today, and I'm going to see if we can drill the rest of the bolt out and Heli-coil it. If I can, it'll be GT40 heads for now...

 

[CDW6212R]

That would be the money saving way for now, save the head.