Has anyone else has issues with heat riser pipes? My 70 W30 presented with a 71 heat riser pipe. There always seemed to be a small amount of daylight between the left side of the carburetor and the bottom of the air cleaner base, where the base sat on the carburetor. No adjustment I made would get rid of that space.

I purchased a '70 pipe at the recent Nationals, installed it, and voilą, perfect seal between the OAI breather base and carburetor. Because of this experience, I'm not so sure these pipes are as interchangeable as some say.

 

I have some original two-oval-hole '70 pipes as well as one or two cotter pin pipes......I'll try to find a car to mock them all up on and make a comparison. Of course, I have no way of telling which year the two-oval-hole pipes came from since the original for my '70 car is likely mixed up with others...but I'll check to see if it may be in a separate box that I may have stuffed it in many years ago (before I got more of these hot air pipes).

As far as the '70 and '71 pipes....FWIW, the Assembly Manuals show the same PN (405259) for BOTH '70 and '71 455 hot air pipes.

 

Good morning 70Post, be certain that I was just making an observation, and I did not intend to make a thread that caused you extra work. However, your offer has my curiosity.

I need to clarify that when I stated the crack was at the left side of the carb—that is when standing at the front of the car. Of course, my issue could have resulted from some inconsistency with the hot air shroud the pipe fits on at the right-hand exhaust too. I fiddled with that connection as well, and that didn’t seem to make any difference with the fit. I thought it odd that the so-called ’70 pipe made the fitment correct between the carb and the OAI base, while the ’71 pipe created a small gap.