[mf67gto]

Does anyone have experience in putting roundport RARE manifolds on a '67 GTO with E-heads? Passenger side no problem. Driver side has some interference. Some grinding on chassis will get it there, but I thought I read someplace about moving the engine back 1/4" or so. Worried about dist clearance to firewall. And if that is done any good methods? I already have 1/4" spacers under frame mounts for oil pan clearance.

I just received these from Paul/RARE and they look great.

Thanks for any guidance/experiences.

[mf67gto]

Anyone?

[Sirrotica]

I have installed 70 D port RA III manifolds in a 67 GTO chassis, the main difference is the exit point, or collector is too far forward to clear the crossmember under the engine, If you look at my signature pictures, the 67 GTO dirt car in the second picture has the 70 D port manifolds on it.

There is more interference than 1/4 of an inch. More like a full inch that the engine would have to be set back to clear the collector, and be able to put the bolts in the flange to the manifold. I used a cutting torch to get the clearance for the install. Of course this was on an old raggedy dirt track car, but I surely wouldn't start hacking a hole in the frame on a street car just to get those manifolds in. Keep in mind my race car had a full cage in it and a hoop tied to the front frame sections to keep everything stiff, so cutting that notch out didn't weaken the frame and cage assembly. You won't have the extra bracing that I had, in a street car, to keep everything from flexing.

If someone was so inclined, they could cut the frame away and use a portion of 3-4 inch black iron pipe welded into the hole that would have to be removed to gain enough clearance for the exhaust. Without a cage in the car I would recommend against hacking the frame, and crossmember apart without a plan to reconstruct the crossmember after material removal. Engine setback would probably be less work, might require a little BFH firewall clearancing. Engine setback will also give you more weight on the rear wheels, with less on the front, win, win for more traction.

I realize your using round port manifolds, but I can't believe that there would be any less interference than the D ports were. Just curious where you got the information that 1/4 inch was all that would be required for adequate clearance on a 64-67 chassis?

If it were my car, and I forked out the money for aluminum heads, I'd be taking all the advatage I could with 4 tube headers, but it's not my car. Lots less hassle than redesigning the chassis to fit cast iron manifolds.

My , it's your car, so you make the ultimate decision.

[mf67gto]

Sirrotica, Thanks very much for all of this detail. I'm not sure the difference between the RP and DP manifolds but I have no clearance issues on the passenger side at all. On the drivers side the bolt boss closest to the cross member is just touching that cross member when I had an old set of motor mounts on it. I see your point when the flange/headpipe is installed. Paul at RARE told me about the clearance dimension issues from his experience.

The current old mounts have a lot of clearance front to back on the frame mounts - approx 3/8" and I have just received a set of the AMES Torqu Lok mts that fit tight side to side on the frame mounts. I will mock all of this up and see where I am. Also checked all the frame dimensions and they are good. This was a 55k mile car when I bought it in 1974. I'm hoping the new mounts might push the engine back a bit.

On another subject I have a set of Dougs 1-7/8" RP headers I had fit on to this car and fitment was tough. Had to flatten one pass tube as it rubbed up against the frame. I will try these with the new mounts again as well. I'm going to find the best solution and then will sell whatever I don't use.

Fortunately the body is off the frame so this is a bit easier to work on.

I'll post again once I get it figured out as this might help others trying to do the same thing.

This forum is invalauble for info like yours.

[Sirrotica]

The left side was the problem when I did it too, nice that you have the body off the frame, makes things easier for this operation.

The class I raced in required cast iron manifolds, no headers allowed, and I had previously had a 70 Judge RA III I used the manifolds off of that car. This was long before RARE was in existance, it was 1977. Finding a pair of 67 RA manifolds was at that time like looking for hens teeth, hence the reason for adapting the 70 manifolds to the 67 chassis.

Well I've spoken to Paul at Pontiac events, and he is probably fairly knowledgeable about his own products. I would have thought that Pontiac would have designed the manifolds very similar between the III and IV engines, but maybe not.

If you decide to setback the engine it's only going to be accomplished by removing the mounts from the frame, moving them rearward, and drilling, or slotting the holes in the crossmember. There is no combination of the engines soft mounts that is going to get you a setback. This usually requires removing the lower A frames from the chassis to access the nuts on the inside of the crossmember. There are a few cars that the nuts can be accessed without removing the lower A frames, but it still isn't easy to remove and replace them even if that chassis affords you access.

You might want to look at a stock 64-67 A body to see how much firewall clearance you have. Just gong from memory the 67 has adequate clearance. First gen F bodys have really tight clearance in that area, but A bodies have more clearance.

As engine masters has already proven on the dyno, denting a header primary tube for clearance has little if any effect on power. I've done it many times over the years, mostly on Pontiacs, but other brands as well.

Good luck in whatever you decide...........

['ol Pinion head]

Several years ago, RARE offered round port exhaust manifolds for '64-67 models. Might be worth calling Paul & see if more are in the works.

My earliest acquaintance with round port manifolds in an early chassis A-body was in the late 80's. Local '65 GTO owner took a sawsall & an angle grinder to the driver side cradle then pieced in two pieces of plate steel. Finished up welding them in with a crackerbox welder, then installed his .060 428 with RA2 heads. IMO, created a lot less issues than moving the engine/frame stands back.

[Sirrotica]

Originally Posted by 'ol Pinion head

Several years ago, RARE offered round port exhaust manifolds for '64-67 models. Might be worth calling Paul & see if more are in the works.

My earliest acquaintance with round port manifolds in an early chassis A-body was in the late 80's. Local '65 GTO owner took a sawsall & an angle grinder to the driver side cradle then pieced in two pieces of plate steel. Finished up welding them in with a crackerbox welder, then installed his .060 428 with RA2 heads. IMO, created a lot less issues than moving the engine/frame stands back.

Paul told him 1/4 inch is all that he needs, simply slotting the holes and sliding the whole assembly back 1/4 inch is less work than cutting, and reconstructing the LR portion of the crossmember. A 1/4 inch wouldn't even make a difference in a cross shaft for the clutch, or automatic linkage because it'a a cable. Even if it was a column shifted automatic, a 1/4 inch offset would still work.

I still have my doubts that 1/4 inch is all that's required, basing it apon my experiences with D port manifolds, I guess we shall see.

To me round port headers are the answer.

I thought that somewhere along the line there were round port manifolds produced from RARE that fit 67 and older. Considering how much trouble he's having just getting the stock pieces cast, I wouldn't hold my breath on getting custom parts soon. I guess it never hurts to ask though.

[mf67gto]

Thanks fellows for the replies. These are the 64-67 RP versions so I'm betting it is why I don't have as big an issue as Sirrotica describes on his car. I just got these recently (2 months ago) from Paul as called me and told me he just got his foundry supplier online. I had ordered them in 2020 but I'm way behind on the car anyway so I kind of wrote them off. When he called me he said he had these units on hand and could ship in a couple of days - which he did.

I did talk with him after getting these inputs and got a couple of good suggestions of what others have done. I'll get the engine back into the chassis hopefully this weekend and take some pics. Then I can see where I am and report back if others are trying to do same. Sounds like some just made it in w/o mods but most have this small interference like I'm finding.

[Skip Fix]

I think a few years ago I talked to Paul and he told me even though it was not published his round ports did fit early GTOs.