A Muncie 319 is a 318 with a Borg Warner overdrive grafted onto it. It has a 4 bolt side cover and the parts ahead of the output shaft interchange with the non-overdrive 318. What you have there is a Saginaw that has had the shift linkage cobbled up to fit in place of a SM-318. The driveshaft is at least an inch too short. It looks like Mr. Bad Pliers has been working on your truck!
Jerry

"It is better to be silent and be thought a fool than to speak and eliminate all doubt!" - Abraham Lincoln
Cringe and wail in fear, Eloi- - - - -we Morlocks are on the hunt!
There is nothing noble in being superior to your fellow man; true nobility is being superior to your former self. - Ernest Hemingway
Love your enemies and drive 'em nuts!