What 340 camshaft?

Johnny Dart said
How bout the 1968 340 4 speed purple shaft cam. :)

Personally, I'd throw the Comp XE268H in and call it a day.

Cause they never made it. THe 340 cam that's the purple shaft is the 69 and later auto cam. Oregon Cam Grinders has the 68 4 speed cam in their lineup. It's like 2* different but that's spot on, IMO. The 268 is a good choice.