will this spline count fit my truck (CL add)

[nolan in blaine]

http://skagit.craigslist.org/pts/2116328368.html

70 f100 302 c4 2wd. Right now i have 3:50 gears.
Im probably gonna pick up an AOD this weekend. If these do fit, should i buy them also? Will they help with mileage much, or will the truck be gutless with the AOD and 3:00s? Will the spline count jive with what i have? Can i just swap over the ring and pinion if not? Sorry about the ton of questions, But im really jazzed about finally doing some mods on this thing

[fordman]

probably not you probably have 28 splines in your rearend. so your axles wont fit.

[nolan in blaine]

can i just swap the ring gear on to my diff to retain spline count?

[nolan in blaine]

http://skagit.craigslist.org/pts/2115925628.html

Also im thinking about picking up this AOD. Its not the "holy grail" as i have heard the newer ones are. But i dont tow much so.... What do you recommend?