Dogface,
No, that is a not a bad idea (a 3.55 torque-tube conversion). The reason I was asking is that Yukon Gear & Axle does not list them. Still, give them a call.
I have done two 3.55 torque-tube rear end conversions, with a friend who s a mechanic. Both went very well.
Chris SWEET has done at least three on his truck and with other people.
In my opinion, if a 3.55 rear is a low enough ratio for you (it is for me at 60-65 mph), the 3.55 conversion is the lowest cost conversion.
Overdrive transmissions are great, but you will need a transmission that is in good condition, a rear end with the right gears (different rear brakes/lines) that are all in good condition, a drive shaft and u-joints, new bearing/seals, and new rear springs/perches/bushings. If I am wrong about these "needs", someone will correct this.
