Case number on Chevy 3sp Transmission

I currently have a transmission that will not shift into 3rd gear. My case number is 591747. I found one that looks just like mine but the case number is 591814. Does anybody know enough about these transmissions to know if they will interchange? It is going on a 51 Chevy with the 216 in it.

Thanks,
Chuck

 

It looks like mine has two holes near the back where it mounts to the cross member. This other one does not. i wonder how it mounts in the rear. Anybody know?

 

That transmission number is from a '53 Chevy with a 235 engine. I'm pretty sure those trannys bolted onto the bellhousing and the housing onto the crossmember cause my '57 3 speed hooks up that way.

heres the link with the info :
http://www.chevytalk.org/fusionbb/showtopic.php?tid/252572/pid/2003621/post/last/m/1/