[unruhjonny]

Although I have the 'Pontiac Bible' (McCarthy's book) - maybe some here don't have it for referance;
I had though that the 67 RA manifolds were essentially the same castings used in 1968?

I know I have some earlier (not repop) castings hanging in my garage, but if my memory serves me, neither of them have a casting date code...

[SD455DJ]

Just FYI...here's a '66 GTO that had a '69 RAIV in it (from a '69 Firebird!) with '68.5 RAII GTO manifolds (found the engine and manifolds in a local junkyard back in the 70's). The previous owner (original) torched the driver side frame & crossmember to make the manifold fit...what a hack job!

Dennis

[Sirrotica]

Originally Posted by SD455DJ

Just FYI...here's a '66 GTO that had a '69 RAIV in it (from a '69 Firebird!) with '68.5 RAII GTO manifolds (found the engine and manifolds in a local junkyard back in the 70's). The previous owner (original) torched the driver side frame & crossmember to make the manifold fit...what a hack job!

Dennis

When I used 70 RA III D port manifolds on my 67 stock car, that is very similar of what the frame looked like after I got done using a gas axe (cutting torch) to make them fit. This was in 1975, long before RARE was ever thought of. At that particular time, the 67 manifolds were as scarce as hens teeth.

Being that the stock car was already headed to a scrapyard when I decided to make it into a race car, I had no worry about modifying the frame to fit the manifolds. The car also had a full roll cage with reinforcements ahead of the firewall, as well as in the trunk area. Cutting a notch in the area pictured had zero effect on frame flex with the cage reinforcing the entire car.

As I have said previously when discussions come up about using the later manifolds on an early chassis, I absolutely would not do this to a street car with out making some type of a fabricated patch to restore the frame integrity after modifying the frame to fit the late manifolds.

There have been people that have said you don't have to hack the frame when swapping in late manifolds into early chassis, but the real GM D port manifolds will need this frame section removed. I've never owned any reproduction manifolds, so possibly the dimensions aren't the same as GM manifolds I know Paul (RARE) had stated in his ads that his manifolds were exact reproductions using GM blueprints. However there are other aftermarket manifolds that make no claim that their parts are the same dimensions as the OEM manifolds. That may possibly be the exception that others talk about that late manifolds will fit an early chassis without substantial frame modification, but I do know that the OEM manifolds need help to fit.

Unless the reproduction D port are different dimensions than the original factory parts, they won't fit an early chassis without major surgery. Thanks Dennis for that picture, it illustrates exactly what I have said repeatedly on the forum. My old racecar went to the crusher about 1978-79 so I have only the one picture of it I use in my signature picture in victory lane.

Dennis do you know what happened to the 66 in your pictures, was it ever restored, parted out, etc.

[SD455DJ]

Brad, these pictures are from last summer (2024) when my brother Dan 'found' the car in a barn (true barn find!). The '69 Firebird RAIV engine actually was running the original '66 4-bbl intake and carb along with the original ST300 2-speed auto trans with a 3.23 Safe-t-track. Dan pulled the engine and sold the carcass to a friend who is now using it for yard-art.

Dennis