Don't buy an Accufab if you want to use a 75mm tbody, they are designed for a 70mm tbody. Go with a C&L, Trick Flow, or Dragon, I believe all of those will work fine with the 75mm tbody. You can port a stock tbody to work pretty well to work pretty well with a 70mm tbody, which is about what an Accufab looks like a polished on the outside, polished and ported stock plenum.
Rick Kilpatrick, AAS Automotive Systems Tech, Alamance Community College, Class of 99. 06 5 speed manual Mustang with Pony pkg : GT Mac Mufflers, true duals with one custom pipe. 2.5" system. GT bumper cover, all installed March 7&8 2006. AFE Stage 1 CAI, Motoblue Underdrive pulley, GT aluminum shifter knob, honeycomb rear blackout panel,and dash kit installed. Roush hood scoop and side window louvers installed. SS taillight trim has been installed, new alum. GT steering wheel installed.