I have a Canadian built 1982 F-150 with the following on the transmission and rear axle

from the tranny tag
GD-BC17-F7
E3TP-BA-15353 from door tag trans code "K"

From Rear Axle Tag
WDM-CJ-2F03
2-75-9-5314C from door tag AXLE code "18"

My questtion to you fine folks, is what are these first, and what good combination would give me overdrive as replacement.

Thanks!

 

K is the C-6. The AOD would be the easiest automatic to swap in to get OD, but if you're looking for a manual (you didn't specify), it's gonna take some more effort & ca$h. The M5OD-R2 is a medium-duty trans, but it's almost as expensive as a ZF S5-42. Remember that you have to match the bellhousing bolt pattern - what's your engine? If you don't know, post the 8th digit of your VIN number (or the whole thing minus the last 5 digits).

The second line of the axle tag says it's a 2.75 ratio open diff 9" axle, but the door code says it should be a 3.08 ratio. Looks like someone swapped it.

 

Will overdrive with a 2.75 rear work? The engine rpms will be very low with that combo.

 

Sorry about that, it is a 4.9L six and I would prefer to stay with an Auto. I know....... Kinda wimpy, but I'm getting soft in my old age! The rear end swap surprises me. My complaint with the drivetrain is that it is taching the engine up at highway speeds. Sounds like it would have been worse with the original rear axle.

 

"Will overdrive with a 2.75 rear work" you can but in the long run you will probably fry the tranny, i hadd that same gear and the 4sp od manual tranny in my truck and it fried the clutch and flywheel (ever seen a flywheel cracked like a dry lakebed that hasn't broke yet?) You can go 3:1 gears and the od tranny, that would give your truck a little bit more grunt to.

 

That would explain why the truck is a little numb out of the hole. Sounds like I need to change both tranny and rear end to get what I want. Does anyone know who made the rear axle and what it came out of? Will this combo fry my transmission, or can it take it. Engine knocks a little on take-off, timing at spec, bearings etc new, engine free of carbon.

 

the AOD and 3.50s is ok, and the C6 with 3:1 gears is good too, but they don't give really great down low grunt if you use that combo to tow, but they are good for cruisin. probably a good combo would be the C6 and 3.50s but you can always put a shift kit and 3.73s in the AOD combo to wake it up quite a bit.