you answered your own ??? stick with shorties if you just want ground clearance......my own xp at my buddies shop with a dyno is shorty headers do in fact increase hp/torque over stock manifolds......and the only stock manifold worth a crap was the hipo ones which do not work on mavs......I have seen gains of 5-18 hp over manifolds with no exhaust bolted up......
Here's a good read, on the subject: http://www.mustang50magazine.com/techarticles/29618_short_long_tube_headers_test/index.html Since I have run both long and short, on a Maverick. The best thing about the short tube headers, is the ground clearance..I've got a 20+ year old set of Headman long tubes that show the battle scars. The engine in my car now, has been in 3 different Mavericks, (long and short) and it still hauls a$$ with either header.
