Headers can be a PITA, and more so if they are not of good quality. Looked at a 2nd gen bird the other day with a big block chevy in it and was surprised how much room the headers had. Not so with a 1st gen bird. Power steering box clearance is especially tight. Log manifolds should be ok for 300 to 325 Hp with no headaches, leaks etc. If you really want headers look at the long branch cast iron or check out high quality headers made for your 1st gen bird.