I plan on installing a 5 speed, OD trans. I was told a 6 speed requires too much cutting in the cars tunnel and I don't want to butcher up a 70 Mach 1 any more than I have to. I am also looking at Gear Vendors OD units,http://www.gearvendors.com/index.html,
that bolt on the Ford 4 speed top loader. That would give my eight gears forward. I probably would never shift all eight gears, but they are there. I have no idea how they are compaired to a 5 speed trans. Cost wise, the GV OD may be cheaper. You may be right. Some of the 351C engine shops told me to stay with a 383 stroker because a 408 may have too much street torque. I think the cam shaft would have to do a lot with the torque curve. I am also have thoughts of burning E85 fuel instead of gasoline. E85 is all over Northern Illinois and would be over a dollar a gallon cheaper than premium. I'm just not sure about the compression ratio. Any thoughts? Thanks.