OD for big block fords?
 

I have a 77 Mercury Cougar. It has a 351m, which as far as powerplants go, is a sad puppy. It's an engine that gets small block power with big block fuel economy, the worst of both worlds.


I don't want to pull the engine since it works fine, but the 351's status as a big block means that my choices are limited when it comes to alternative transmissions. Problem is, I don't know what my choices are. I've heard something about a 5 speed for trucks that might work, and on the $$$ side I've heard about people getting adapter plates and pulling a AOD from a crown vic, but past that, nothing. I want the most driveable transmission for the buck, and I need ideas about the application and the cost.

Any help, guys?

That would be the crown vic tranny with overdrive then.

Here is an article about "Ford AOD Overdrive Transmission-
Create a conservative Cougar or a miserly Mustang" from Hemmings.
I hope it is what your looking for.

https://www.hemmings.com/mus/stories/..._feature5.html

Thanks much, though it doesn't really help in terms of finding out what other tranny's are out there... it assumes a small block bell housing, which my engine doesn't have.

You need a GearVendors Over/under drive unit.

bulletcatcher, I believe the trans you want is the E4OD. They should be quite plentiful. I don't know what type of trans controller you will need. Baumann Engineering may have a solution. I could be completely wrong as I'm pulling all of this from the deep dark recesses of my brain.

Call up a local auto wrecking yard and ask them to tell what interchanges from their Hollander manual: they're usually quite helpful to tell you. If the first 'yard isn't helpful, call another, and another until you find one that is.

Another thought - you'll likely need shorter gears in the rear end. The mechanical advantage should perk the car up a bit.

try an 80's F250/350 tranny from a 460pick up/van as the 350M/400 use the "big block" bell housing shared with the 460 engine