390 header and cyl. heads.

[matt souders]

Hows it going new to the forum. Just had a couple questions about a build of mine. I have a mustang and was woundering about cylinder head and header combinations. Just started reading around on diferent forums and noticed talk about heads and header problems. just didn't know if any knew of what headers work with what heads in a 67mustang.

[jayb]

Welcome aboard, Matt.  If you have a 390 GT engine in the Mustang, the exhaust ports are physically lower on the heads than they would be on an earlier FE engine, or on a 428 Cobra Jet engine.  Difference in the port heights is around 1/2", if I recall correctly.  If you try to put headers for the higher exhaust ports on heads with the lower port location, you will get an exhaust leak.  Vice versa is the same way. 

There are ways around this, such as slotting the bolt holes of the headers to make them move around on the head and allow them to fit.  But its probably best to get the headers that were designed to fit your heads.  One header manufacturer that I know of, FPA, makes both low port and high port style headers for early Mustangs.  So, you just need to figure out what you've got for heads, and you can get the right headers.

[ScotiaFE]

Welcome Matt.
The mismatch is about .200" between the low port and the mid port.
The issue is not that bad.
You will need to slot the header bolt holes up so you can move the header down.
The use of a high quality gasket will help also.
I have never used FPA headers so can not say how they fit.
My experience is with Hookers. Mostly the headers.
I have some more pics about this issue, but they are on a different computer.

[jayb]

MOSTLY with headers, Howie?  LMAO!   

[matt souders]

Ok Thanks I'll check into the fpa's never heard of them before. I'm assuming you have previuos experince with this annd like the. has anyone had any experince with doug's headers. A friend recomended them but I've never used the before and was looking for feed back.

[matt souders]

oh I forgot to ask about the bolt patterns. do most manufactures make there flanges to fit all three bolt patterns or do you have to specify the bolt patterns.

[jayb]

The FPAs work pretty well, and they give excellent ground clearance compared to most of the other brands.  I have no personal experience with Doug's headers.

The 390 GT flanges will be different than the standard 8 bolt flanges or the 428CJ 16 bolt flanges, so you have to know what you've got in order to specify the correct headers.

[cammerfe]

I used Doug's on a small-block many moons ago. Quality was just fine and they fit very well. I've not used them on an FE engine however.

KS

[MustangGT]

Don't mean to hijack this thread but have anyone in here tried the JBA headers in a 67-68 Mustang? They sure looks nice but I'm worried about clearances in general, also ground clearance.