Hot Rods what transmission for gmc 270?

flattie, I am running a GM variant of the A833 4 spd with OD in 4th gear behind my 270 w/3.73 gears in a 12 bolt limited slip and it cruises nice at 60mph @1900 rpm or so. Rigged linkage to shift with the stock column shift and added a pull cable to get reverse from a handle under the column. I have driven it to San Francisco and to Minneapolis and back . . . sweet road truck.

 

Thanks for your input,I know I will pick your brain when I decide and when I start working on this particular project,there's 2 in front of this so for now I'm just gathering parts...



I was given this 54 or newer 3 speed and a 49 3100 stock running gear/4 speed on the floor,closed drive rear end and juice brakes in front...options.
I'd the ,49 4 speed or 54 3 speed any good?