[Speargun]

Every set of headers I've ever put into a '67 Firebird have needed "massaging" on the driver's side to clear the steering gear box. I went with Doug's headers this time and still had to do some hammering.
After about 8500 miles I noticed an exhaust leak and found the header tube was cracked where it rubs against the gear box. I just pulled it out & tigged it up, but I'm sure that it will happen again.

I'm thinking about going back to a factory type exhaust manifold, but I'm concerned that it may be too restrictive. The engine is +.060 455 (469 cid), hyd roller, 10.25:1, 600hp+/-, with round port e-heads, & 3" Pypes to the rear. It's primarily a street car, but it will see the track every now & then and I plan on adding a fogger system in the near future.

Will the RARE ram air 4 over size manifolds
A) fit? They say they're for 70 1/2-81 F-Body
B) flow enough?
Are there other options out there?

Thanks!

[69camarox]

the rare manifolds will not fit your car
apparently ram air restorations at one point made the round port long branch manifolds but no longer make them .
original ones are hard to find and expensive

[tom s]

My Ames catalog shows FN388F as 67-69 firebird Super round port RA manifolds with 3in ID collectors for aftermarket round port heads.Tom

[Speargun]

Originally Posted by tom s

My Ames catalog shows FN388F as 67-69 firebird Super round port RA manifolds with 3in ID collectors for aftermarket round port heads.Tom

Discontinued

[tom s]

bummer

[69camarox]

and those few aftermarket ones that exist cost as much as originals

[Donovan]

Is it possible your engine is too low in the bay? Tweaked mount plates or something similar. I ask because you say every set you've tried need hammering.

[Speargun]

Originally Posted by Donovan

Is it possible your engine is too low in the bay? Tweaked mount plates or something similar. I ask because you say every set you've tried need hammering.

I custom made my motor mounts so the engine does sit down a little bit lower than normal, but even when I had Factory type mounts in the past I've always had to hammer the driver side header.
Now that I have a cowl induction hood I may redesign my motor mounts to raise the engine some.

[Sirrotica]

FWIW, If your using the stock style mounts you can just take a flat steel plate with a 1/2 inch hole in it, and make spacers to go between the frame mount and the motor mount.

[wovenweb]

Originally Posted by 69camarox

and those few aftermarket ones that exist cost as much as originals

Interesting, and I was looking to just get mine replaced with ceramic coated RARE D-ports when and if I change them out.

FWIW, when I ordered my RARE round ports from Ames 8-9 years ago they had one other set at the time. Paul was out. I guess this is one of the few times in life my timing has been good.

[69camarox]

d ports are no problem the round ports are the ones that are hard to find

[Inogame]

Huh, I wonder if there is that much play between individual subframes.
I have Doug's on my '67 and the driver's side fit right in from underneath with no hammering nor interference.

I did replace my motor mounts as mine were cashed. I used the poly mounts from Butler. It's possible they sit higher.