68 barracuda Exhaust Q
I'm assuming that your talking about the driver's side down pipe?? If so then to answer your question, you might could use 2 1/2 but I can't see going through all that trouble since the exit hole on a 340 manifold is only 2 1/4" (at best). The exhaust can only flow a freely as the smallest diameter in the system. So even if you used 3" pipe the 2 1/4" manifold would restrict it either way. You, or someone else, would have to custom make the down pipe. Even with 2 1/4" pipe it's extremely tight!! I used to make them but haven't made one in years:
I'm assuming that your talking about the driver's side down pipe?? If so then to answer your question, you might could use 2 1/2 but I can't see going through all that trouble since the exit hole on a 340 manifold is only 2 1/4" (at best). The exhaust can only flow a freely as the smallest diameter in the system. So even if you used 3" pipe the 2 1/4" manifold would restrict it either way. You, or someone else, would have to custom make the down pipe. Even with 2 1/4" pipe it's extremely tight!! I used to make them but haven't made one in years:
