The Engine side Reverse Switch Harness should have a short pigtail from the Black w/White Tracer Wire out of Cavity C of the Wiper Motor Harness. Run this Male Bladed Pigtail to Cavity Z of the Headlight Harness.
Under the Dash- Reverse Light Black w/White Tracer plugs into Cavity Z, and it's an assembly line add on so the wire simply gets a couple of friction tape wraps outside the main harness. Purple Ground Wire bolts to Dash Frame with a #10 self tapping screw. Hope the pic helps.
And Hell Yeah! Big difference driving a 4 Speed!
Congratulations!
http://www.tonysparts.com/newproductsB.htm
Tony has the Dash Light.