Anyone install three speed with overdrive behind a slant six

jonn6464 said
Sorry to hijack this thread, but I've always wondered this...
I've just bought an A833OD, so hopefully I can get some clarification here.

"So when you shift the OD box, shifter 1-2-3-4, the box itself goes 1-2-the old 4-the old 3--which is the OD gear".

-When the shifter goes from 3 to 4, but the box goes 4 to 3, won't the engine "rev up" like it would when you downshift a normal 4 speed tranny into 3rd gear?
-If you turn the 3/4 lever back around and have it pointing up (and then use the correct linkage arm), would the box revert back to shifting 1-2-3-4?

Thank you for any help.

Yes, but with the 3-4 lever up the car would go from 1st to 2nd to O/D then 1:1. So with the 3-4 lever down the O/D is a higher gear, say .73 so it feels like a 4 speed with the gears spread farther apart.

64-70 standard gear ratios: 2.66, 1.91, 1.39, 1

77 up O/D gear ratios: 3.09, 1.67, .73, 1.00