Back when I was wrenching the big rigs, some guys would convert Roadrangers to OD by swapping two gears on the countershaft. Don't remember the exact procedure, but it was a pretty common modification for the shops that did their own trans repairs.
Jerry
Edit: I believe I've heard about some aluminum block 4-53's out there, in some sort of military application. Anybody got some definite information on them?
Jerry
Last edited by Hotrod Lincoln; 11/21/2007 7:20 PM.