Ahh, got your pic. B427 means "industrial" (B-6427 is "automotive" and PB427 would be "power unit", but I don't know how Cont defined those).
My pic a little fuzzy, but looks like "spec" 745, which I would guess-repeat,guess-means carb, dist, cooling? maybe cam, timing?; maybe someone knows.
The 50 Motor book shows (for b-6427):
Brockway: 48-49 148W,151W,153W; 44-49 152W, 154W (their eng # 42BX.
Corbitt: 48-49 H22TG; 46-49 22TG,25BG; 47 22TGC, TGD; 46-48 35RG.
Diamond T: 47-49 703; 46-49 809.
Federal: 44-47 45M & M2; 55M & M2.
Ward La France: some 46-47 D1,D1C.
NOTES: Book only goes to 49. "Some" means other eng also shown for those models. Believe book only covers "road" trucks, not ind/const models, per larger listings in clutch catalog. T-6427, maybe, repeat:maybe-an OHV variant used in:
Federal: 48-49 45M & M2 & MA, 55MA & MZ, 645M & MA.
REO: 48-49 D23 series, incl L,R,RL,RBL,RT,T; D236.
Ward LaF: 48-49 some D1,D1C,D1T2.
Bearing catalog shows same rod, main bearings for B & T-6427, with other Cont's: 41B, 42B,B371, B405, B427,B6371, B6405, some of which are 4 1/8 x4 5/8, so some B and T variant parts apparently interchangeable. Clutch catalog contains many more, esp Brockway; will send email direct, BUT NONE OF THESE YEARS EXCLUSIVE: many other models with different engines, so no idea of total units using this engine. With Sympathy, Bud