OD box (Volvo M46)

[randybmclean]

I have a '85 300D Turbo and would like to get the revs down on the highway. The rearend is not known but likely 369 or 347. The drive shaft link from the tranny to beyond the hanger looks like a good place for a overdrive box and I am very tempted to pull that length of driveshaft and replace it with an off the shelf or homemade od box with a 20 to 25 percent reduction in rpm.

The Volvo box seems to be a perfect pick, however I do not know if they are available in North America. This box would basically give me a 6 speed automatic tranny while the rearend gearing swap would not allow me to do burn outs. Ha Ha.

All thoughts are appreciated.