[krisr]

Per the title, i've got a 66 GTO and i'm looking to put my 400 into it from my other car. The motor is a fairly healthy 400 with Edelbrock round ports, solid roller camshaft. Originally I was going to get a set of RARE manifolds, but Paul mentioned that I might need to move the engine back 1/2" for the manifolds to clear the crossmember. Being my car is a 4 speed car, moving it back 1/2" is not something i'm very eager to do, so I was looking at the Dougs tube headers (Part D567-B). Has anyone run these in their car? Am curious as to what fitment is like.

Cheers!
Kris

[242177P]

https://forums.maxperformanceinc.com...d.php?t=859647
Pic is from post #22 if you're bold enough
to cut on what I assume is a real GTO

[ID67goat]

While my Doug’s Headers were purchased many years ago and I don’t know if they changed anything on the ones that are sold now, I would say that the fitment is really good. Did not have to clearance any tubes and the ground clearance is very tight to the floor boards.

The Hedman Hussler headers I had before also fit OK, but hung down below the car too far for my taste.

[mf67gto]

Kris,
I have almost the exact same car/engine and problem. Here are 2 links to some discussions on this exact problem https://forums.maxperformanceinc.com...31#post6426831 and https://forums.maxperformanceinc.com...35#post6272335

My set up is a 400 block in a '67 GTO, 72cc e-heads and the same Doug's you list - 1 7/8" as well as a Canton pan. Other folks have said they fit fine, but that was mostly with d-ports and the older 1 3/4" round port versions. The latest versions also have a thicker flange from some dimensions folks on the forum took in one of these threads.

On the Doug's - fitment on the driver side pretty good with just some grinding on the lower control arm mt for clearance and then I would have had to relocate the zerk fitting on the cross shaft. Passenger side was right up against the frame as a couple of pics showed. I was able to slightly flatten one tube and give me a little clearance but I was still not comfortable with it.

At about that time Paul called and he had a set of 64-67 O ports which are different as I understand than the 68 and up. Pass side with 3 hole flange fits great. Driver side per the picture of the rusty frame in this thread was an issue just in that area. I was thinking about cutting it and doing some welding of a piece in there. A buddy told me to get a 2" diameter steel pipe and a torch. The issue to solve is that the radius is gentle there between the cross member and the longitudinal part of the frame. The 2" solid steel pipe (got a 12" off amazon for $20) worked great to tighten the radius up and give the clearance around the one mounting area of the two bolt manifold.

Right now I'm working on the fitment of the Pypes down pipes to the manifolds but I'm going to be good to go. Have to grind the bell of the pipe down to get it inside the studs of the manifolds per Pypes Tech guy.

Also, I have mocked this up with Remflex gasket's which are thicker than what was supplied by Paul and do push the manifolds slightly closer to the frame. Could always use thinner ones if needing just a bit more clearance.

I can take some pictures tonight.

Hope this helps - sorry for the long reply. Be glad to connect directly with you if helpful.

Matt

[65gto69]

My dougs headers for my 65 gto are only a couple years old from new. I have a 4 speed in my gto and I only had to slightly dent the headers to clear the z-bar. I had no suspension clearance issues.

I am running edelbrock roundport heads with dougs d567 headers

Mark

[carcrazy]

67 GTO, 461 with Edelbrock round port heads, turbo 400 and motor mount spacers. No interference.

[krisr]

Thanks all! It sounds like this combination might actually be one of the edge cases where tube headers outflanks ram air manifolds, which is a shame. Cheers fellas!