Doug's does not make a header for a 360 in a 67 Dart only TTi. They given us headers for the last two giveaway cars & they fit perfectly. Even the complete system went in about 3 hrs in the 67 Dart. Nice fit overall.
Why wouldn't the Dougs fit a 67 w/360. I've never seen anyone with a 67 SB car have a problem when using factory heads. 67 has the same basic engine compartment as a 68-72. Summit list the D453 for that application.
tti used an old set of Dougs as the basis for their routing. No plug wire issues with either, Douge or tti. New style Dougs do not have the slip tube that goes around the T-bar. Dougs are 1 5/8" tube. Dougs are not stepped. In my experience, the step doesn't do a whole lot.
I've been very happy with the Dougs that I have and would spend my money there, 100 more times than spending an additional 200-300 at tti. If it was a race car only, a tti header wouldn't be anywhere near my car.