1979 F100 Ranger trans fluid?

[Figor]

Hello men, I've got a real head scratcher here and need help.
I have a 1979 F100 with the 300 six cylinder and an automatic. I dont know which C series trans it has but I need to add fluid. The issue is I know Ford switched fluid from type F to Dexron/Mercon around 1976. So why does the dip stick on my 1979 trans say Type F? Now I dont know what to put in it. I do know if Dexron/Mercron is put in a trans that should only have type F it will trash it. So you see my delima here. Any advice is appreciated.

 

[DaveBen]

If it says Type F, use Type F.

 

[Figor]

I did but it just seems odd that a truck made 3 years after they change would call for Type F. Make me wonder if someone needed a dip stick and just got one from a salvage yard or something.

 

[Rdnck84_03]

It is also a 47 year old truck, It could have had several trans swaps by now. That trans could be from something older.

James

 

[Clb]

If it says Type F, use Type F.

Dis^^^
Someone could have swapped out the trans, or ford had overstock?!