A-Body Header fitment w/small block and 727

I am looking at buying a set of either Doug's Headers or TTI's for my 71 Dart. The car is a column shift 360/727. I have a 73 and up steering box and steering link. Jegs site says they wont work with 727 nor column. Can someone please tell me why they wont fit please?

Call Doug's direct. I had to do that and they are
quite helpful.

Doug's is now own by a company called pertronix since Jan of 2005. Now when you call you get someone who is reading exactly what their website says. And the lady I spoke with was in no way a car person. Thanks it was worth a try, unless i just got a new person.