OLD thread, wondering if any of the knowledgeable folks are even still alive!!
I have a non running 1980 F-350 with a 4 speed. Door code says "F" for trans type. Is that a code for the T-18 or NP435? If I don't sell the whole truck, I'll roll it over and take a look at it. If it is worth pulling, I'll pull it out with the truck upside down.

 

I moved you to your own thread.

Type "F" is Warner T18.

https://www.garysgaragemahal.com/tra...ion-codes.html

 

Thanx for the link!!

 

BTW the T18 and NP435 inter change as I did it on my 81 F100
IIRC they each have a little different gear ratios between them with 4th being 1:1 and first a granny gear non-syncro
Dave ----