I suspect any Chevy/GMC transmission up to the mid 60's would work;Fumblin'46 would be more help on that. Providing it's in decent running order,you can probably sell the 390 for enough to buy all the replaceables for your 216 install(clutch,water pump,tune up,fuel pump,carb kit,alternator conversion,etc.),maybe a tank of gas,too.Good find! Enjoy!
Speed

1954 GMC 350
1957 GMC 1/2 ton
1962 Chevy C-30
1952 Chevy 6400 dump bed project truck
'98 Harley FLSTC
'66 Pontiac Catalina
'76 Chevy 1 ton Duallie
'84 Bronco II
'78 Dodge W-200
'81 Toyota 4X4 truck