Pontiac GTO Forum banner

1 - 14 of 14 Posts

·
Registered
Joined
·
7 Posts
Discussion Starter #1
Installing a 69 400 in my 65 GTO will the Ram Air IV exhaust manifolds fit? Would like to use them if possible.
Thanks
 

·
Registered
Joined
·
602 Posts
RA IV exhaust manifolds would probably work with any round port Pontiac head that has the necessary bolt holes.

Reproduction D port exhaust manifolds are available though and they would probably work well for your application.

Sent from my SM-G930V using Tapatalk
 

·
Registered
Joined
·
3,931 Posts
either way the RA reproduction manifolds are a much better fit in the car than headers and flow nearly as well. Put them on mine and will never put another pair of headers in a Pontiac unless it's pushing over 500 HP.
 

·
Registered
Joined
·
7 Posts
Discussion Starter #6
Using Edelbrock round port heads. Was wondering if they will clear a-arms and frame on my 65. Thanks
 

·
Super Moderator
Joined
·
5,782 Posts
Using Edelbrock round port heads. Was wondering if they will clear a-arms and frame on my 65. Thanks
Well, I would have thought they'd work but I got curious and just called Ram Air Restoration myself (https://www.ramairrestoration.com/contact-us) and asked. The guy says they won't work because of interference on the driver's side with the frame.

Color me surprised.

Bear
 

·
Registered
Joined
·
7 Posts
Discussion Starter #8
That's good to know. Looks like I'll be using headers. Thanks Bear I appreciate your help
 

·
Super Moderator
Joined
·
5,782 Posts
That's good to know. Looks like I'll be using headers. Thanks Bear I appreciate your help
Good luck! Obviously I don't know my 65's as well as I do 69's :D --- Maybe GeeTee knows which headers are the least painful on 65's --- they all suck, just some suck less.

I too have round port Edelbrocks on my 69 and am running Doug's D567's on it. To get them to work, I had to make some changes:

Relocate the brake distribution block from the inside of the drivers side frame rail to the top.
  • Convert to a mini-starter, otherwise R&R of the starter on the drivers side would not be possible without loosening the header.
  • Re-bend and re-route the rod that operates the 'back drive' linkage between the transmission and the steering column lock.
  • Re-route the transmission cooler lines away from the passenger side header to keep them from getting heated
After that, still if/when I remove the passenger side lower control arm I'm going to have to move the header out of the way in order to remove one of the bolts. If I were to turn the bolt around backwards so that the nut end is next to the header, the end of the bolt that sticks out through the nut would wear a hole in that tube - that's how close it is.


Other tips:
I like RemFlex graphite gaskets
'This time' I replaced some of the bolts on both sides with studs. This makes it a LOT easier if you ever have to loosen and reinstall the headers because you can "hang" the gasket and the header on the studs and not have to try to hold them both in place while you start the bolts.
If you want protective coating, the way to go is to buy bare headers and then send them off to JetHot for coating. Their coating is better - especially if you get the upgraded "extreme heat" coating. I had mine done in a dark blue that goes really well with the 69 silver blue metallic engine paint.


I have no direct experience with other brands, but I have "heard" that MadDog headers fit well.

Bear
 

·
64-67 Expert
Joined
·
8,569 Posts
Are the head heights different? I'm asking, because two of my friends are running the RARE cast iron HO exhaust manifolds on their '65 GTO's with zero issues. They perform and sound great. With no exhaust leaks. Another friend has HO manifolds on his '67 GTO.....again, no issues at ALL. I've run Hooker, Hedmann, Eagle, and other headers on early GTO's....and ALL of them were a PITA to install, required mods done to the headers AND car to fit, and all eventually leaked. I hear Doug's are about the best fit these days, but I would definitely go with cast HO manifolds on an early GTO. The trick to install them on the driver's side is to put the bolts into the manifold holes BEFORE you lower the manifold down into the engine compartment. If you try to put them in while holding the manifold to the head, the bolts will be too long to maneuver into place. But if they're already inserted into the holes, piece of cake. All of the cars above have been running these manifolds for many years and thousands of miles with zero issues........
 

·
Super Moderator
Joined
·
5,782 Posts
Are the head heights different? I'm asking, because two of my friends are running the RARE cast iron HO exhaust manifolds on their '65 GTO's with zero issues.
Is that a fact? I would have thought they'd work, but the fellow I talked to at R.A.R.E. said no on 65's. Hard to argue with success though...

Bear
 

·
64-67 Expert
Joined
·
8,569 Posts
Yes, but they are not round port RAII-RAIV manifolds. They are the D port version the HO cars had. Both the '65's are 4 speeds, so they even clear the clutch linkage, etc. Perfect fit.
 
1 - 14 of 14 Posts
Top