if you have a 351 you'll be fine, if you have a 302 then you'll have a problem.
if you have a 302 you can either run shorties or full length JBA's approx 800.00-1000.00 bucks. Or if you can find any long tube set that clears a C6 behind a 302 you would be fine.
i'm using a set of 351w headers on my 302/347 but i had to use a 1/2" spacer on the motot mount so the long tubes wouldn't hit the steering box.
I'm running hooker competition full length headers, they are on a 302 with no problems. Tight fit, yes, but there is a very small amount of clearance between the headers and the AOD.