I have two questions regarding the differential in a 64 F100.
First should it be a Ford 9 inch. like the one in my 65?
And should there be a tag that will tell me if this is a limited slip differential and gear ratio?
Thank you for your reply.

regards
Mike

 

Check this Fordification chart.

https://www.fordification.com/tech/rearends_ford01.htm

See the 1st 4 listed covering years you are questioning. See the tag breakdown and ratio shown with 3 00 as standard and 3L00 being equa-lock. In the left column code, that code would be on THE warranty plate of the vehicle, yours, if original to the truck. If 64 differential is just the center section and tag lost, inspect the center section for spider gears, (standard). Imagine meaning, NL are Non Locking and L are locking.

Hope this helps, Cap

 

The 9" was not available in F100's with Limited Slip until 1968. 1959/67: If people wanted Limited Slip, Ford would usually install the Dana 44.

1963/67, there was also a Dana 60.2 and 60.3 available with Limited Slip.

F100's with A/T usually have a 9" with 3.25 gears. With a M/T, the 9" axle ratio is usually 3.50-1

Plus there was no 3L25 jazz back then. If the truck had Limited Slip, there was a separate ID tag on the rear axle with an L on it.

My former 1965 F100 that I bought new, had the L tag.