First time long time. I just rolled out a rearend out from a 77 ford pickup 1\2 ton, and the tag I found on it reads like this. WDM BC2 5MC then along the bottom is 3 00 9 386D. Can anyone tell me what size rearend this is and what gear ratio? I think it is a 9 inch with a 300 gear ratio. Has anyone used this 300 behind a small block? It's going under my 53 F-100. I enjoy reading everyone's post, had the truck for a while and now starting over, I'm down to the fram and trying to decide which ifs to use. Thanks in advence.

 

Stock rear for:
78 Bronco
75-79 F-100
75-79 F-150

31 spline axles, non locking, 4 pinion gears.

This is one of the "super duty" 9"rears that will work nice with an automatic.
A bit too tall for stick shift but you can swap in other 31 spline compatible clusters.

 

I used a 3:00 gear behind a small block in a 29 Ford and it was pretty doggy, but a lot depends on what transmission you use. If I had it to do over I'd use at least a 3:50 gear. A 3:00 gear behind a big block with a lot of torque seems to work out better.