Correct me if I'm wrong, but the original 1955-57 Thunderbird driveshaft diameter is two inches. For those of you who are now making in the neighborhood of 300 hp, have you gone with a larger diameter driveshaft? There seems to be plenty of tunnel/exhaust clearance for a larger diameter driveshaft. I don't expect rpm to exceed 6,000, if that, and seldom seen. I'm replacing the Fordomatic with a C4, using a Flat-O Products adapter kit. Gene says the driveshaft needs to be lengthened 3 inches. If you've been down this road, what do you recommend?