well i had all my exhaust ran on my 72 f-100 360 4spd 4x4 monday and i am very happy with the results. i had to fight for 2 days to slap on the hedman headers due to the fact they fit so sungly to the block you have to remove anything and everything to get them on then try to figure out how to put the stuff on you had to take off. but the set up is headers, 2 1/2" true duals, Flowmaster 40's, 45 deg. angle rear exit tail-pipes with 4"x18" hedman "bigwazoo" stainless tips. and to my surprize its a little more mellow than i originaly planned on but it sounds sweet! i figure the mellow will get kicked out the door when i thow in the cam along with intake and new carb. but just wanted to drop a line to say iam very happy with the results and if anyone is thinking about a similar set up i recommend it.