[Sirrotica]

FWIW, the outlet to the down pipe is further towards the rear of the car on the 67 manifolds. The 67 GTO dirt car in my second signature picture has 1970 Judge RA III manifolds on it, because rules stated you had to use cast exhaust manifolds in that class.

I had to do some creative surgery on the crossmember that is under the engine to make them fit because the later manifolds have the down pipe connection further towards the front of the car. Without cutting into the crossmember and removing some of it, there is no way they'd work on an earlier chassis.

I would never attempt to make them fit on a nice car, the clearance modification was done with a cutting torch. Stock cars don't have to be pretty, they just need to be functional. It worked, and the car was faster with the RA III manifolds.

I have no recollection of how I wired the battery cable etc, I'm sure it wasn't pretty, but it didn't have to be. The pipes from the manifolds rearward were made from driveshaft tube welded to the original stubs of flanges and the flared OEM pipes. Again, not pretty, but low buck, low restriction, and functional.

Later on we used those same manifolds on a 72 Firebird chassis for another dirt car, and they fit fine, with no modifications.

I still have the manifolds on a shelf in the garage, 44 years after I put them on the 67 GTO (1976).