running a tube front end probably opens up more room so either will work.
the tti are larger tubes and larger collectors then the dougs. not sure if that makes a difference for you or not.
with stock suspension i'd personally go with the dougs. helped a friend install the tti in his 66 cuda. i don't think tti designed them with large (1") torsion bars in mind because they are freaking super tight. the dougs would give you a little more wiggle room..
