I googled the number and it came back as circa 1956 possibly truck. A GM casting number starting in 372 is by definition an early part. When you say Muncie are you meaning an aluminum 4 speed?
Good chance it will have a larger register hole than an aluminum Muncie 4 speed (NOT a compound 3 speed). I would say, don't try to substitute it for a Tri-Five passenger car bellhousing; fine and dandy if it's for a truck application. Yes, it can be "made" to work. I'm basing this all on your avatar of a 55 Chevrolet hardtop. Those car VS truck bellhousings look very similar, but they are't; get the right one to start with. JMO. I am Butch/56sedanhdelivery.
Thanks. Was planning on using my ‘55-‘57 bell housing. He is going to go auto so the bell housing will be available.
The trucks didn't get a larger hole in the center until 1968, with the introduction of the SM465 trans. The 55-56 truck bellhousing is very similar to the car version, but the mounting ears are different.
I learned this the hard way when I swapped my 465 to a M21 in my 68 C10. Prior to 67 as stated they are all the same size hole, even for the truck 4 speeds.
a 55 or 56 truck could likely have a Muncie 318 three speed trans. yes the truck bell has two holes in the mounting ears. the 55 thru 57 passenger bell has two bolt holes on each mounting ear.
Also trucks had two through holes at the lower bolt holes where the transmission bolts to the bellhousing, while the car bellhousings have threads in all 4 holes.
The one in my car comes up as a '55 Chevy and has a small bearing retainer hole. I have had it since '81 and have used it in a few cars, someone told me it came from a truck. Thanks to the internets I could look it up. The iron ones have advantages over the closed-bottom aluminum ones at least for me.
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