Hellsfire, thats easy. It's an adapter plate for the Finnegan Pin to Johnson Rod connector on a pre 48 Gaffinator. VERY RARE.
O.K.,... I might be way off base on this, but I did see something like that years ago, to adapt a add on overdrive to a transmission,......
Thanks for the serious comments! Others were quite funny! For those who commented on a value, I never asked! Go pound sand! LOL! Now I have a direction for a Jeep/Chevy trans or overdrive Google search. Really, thanks to ALL that responded. Just poking at ya!
GUESSTAMATE!! I'd go with the Chevy-Jeep or Chevy to toploader like early Mopar. Big pattern would be the Chevy bellhousing. Small pattern really looks close to old MoparGot a couple of those here. The thickness of this would go along with that as the Mopar had a long input shaft. give us some dimensions of the bolt patterns.
Cool! I will get some measurements soon. It is at my shop, not here at the house. Thank you guys very much!
Update. Still not positive on the application. Has HOOSIER 4KF2 on the bottom. Large side fits on a '79 460 Ford bell.