yet another trans question
 

ok guys, looking on craigslist cuz i posted an ad for a car for my freind, and stumbled across a listing not even a half hour old, its a 1988 f150 with the 300 6 and a 4 speed with overdrive standard transmission, my question is is there anyone who could tell me which trans it would be more likely to have, and would it be suitable in my 90 f250 ( durability wise ) i dont wanna drop the money if the trans cant handle the power, initially i will bolt it to my 351, but if the 351 dies, i will rip it out and drop the 300 in it. any ideas guys, and thanks for the help

Not an expert but my guess would be an AOD which would not hold up with your 351 without internal mods. If you could get the guy to give you the trans code off the door sticker or count the pan bolts you would know for sure.

i thought the aod was a automatic transmission, this one in it is a 4 speed with overdrive standard trans

An AOD is an automatic.

If it really is a four speed overdrive then it was swapped at some point. Ford stopped using the four speed overdrive transmission by 1988. That was not a very durable transmission anyway and wouldn't be very well suited to your F-250.

However, it's very common for someone to call a 5 speed overdrive transmission a four speed with overdrive. They don't understand that the number refers to the total number of forward gears including overdrive. So it could have the M5OD, which is also not super reliable and wouldn't be good in a tow vehicle.

But... in 1988 Ford used the ZF 5 speed in a very few 1988 F-150's. It's possible that truck has the ZF 5 speed, which would be a very good transmission in a tow vehicle.

If the owner is way off it could be a four speed without overdrive. These transmissions had a granny low 1st gear and are super strong.

Best way to tell... look at the door post sticker code and count the number of forward gears.