have a 71 340 duster which I believe is has all correct engine components.
my question is this....when looking at other 71 340 dusters most have the early style exhaust manifolds(68-70)
door sticker build date is 12-70
was told that early builds had the 68 style and at some time they changed over to the log style
so how do I tell which ones are correct for me as I need to replace the head pipes soon.

Thanks for all replies
Bennoel