I have a 1974 maverick with a 300-6, bored 40 over with a hi-po cam, hi-po head, offenhuser intake with a 450 cfm 4-barrel carb with ram air. I have a 4\11 posi track rear end under it. Hears my question. I want to put a 3-speed auto trans with overdrive in it. What kind of trans do I need and what can I get it out of. The engine is out of a 1988 truck. I talked to someone on your site about this befor and they told me what I needed and what I needed to set it up.I think they said a trans out of a older lincoln or there were a couple others. I beleive I neded an special kit to set the linkage system up with. Can you point me in the direction for the things I need? Thanks. Steve. success@reliable-net.net
Any AOD or AODE that fits a small block Ford will also bolt to the 300. You need a 164 tooth zero imbalance flexplate with an 11.4" bolt pattern from an automatic 300. From there, it's the same drill as putting an AOD behind a V8: TV cable, crossmember, shifter, cooling lines, driveshaft.
The AOD from a Lincoln Mark VII 88 up or one of the big cars will be the better units to use. I think you will have a lot of low and mid-range torque with your setup. Sounds like it will be a blast to drive. I tend to like lots of low and mid range torque. 4.11 rear might be a tab low but thats up to you after you live with it a while. My daily driver is a Mark VII with a Baumann AOD shift kit and blown 5 L engine and 3.27 gears.
I had an AOD from a 91 Lincoln hooked to the 250 in my Mustang. The same setup would apply to a 300. I drove the Mustang this way for five years and it was a nice cruiser. I would invest in a good shift kit, at a minimum, to firm up the shifting.