Pete,

Brownies come in sizes dictated by torque rating of the engine: 5500, 5800, 6200, 7000, by dropping last number of model, I. e. 5800 unit capacity is 580 ft.
lbs. of engine alone. Ratios can be found by googling, denoted on unit by letters after the torque rating. Uses standard bearings, no output shaft seal, reverse threads, not a problem. Standard Speedo output on rear.

I have several that had larger engines and running gear larger than stated, one concrete mixer truck with big GMC V-6 engine with 5500 Brownie.

No ‘speed shifting’ these, unsynchronized, but are easy to shift using common knowledge!

Search yard oneself, if call, they will not know what you are talking about. Look for extra shift lever in cab. Make sure and get shifter and rod ends, rods are easily made with water pipe or EMT.

7000 and 8000 models are semi truck size, 5000 and 6000 are big enough for most common size trucks unless a ‘hot rod’ truck. They are heavy, use rubber mounts, one mount is circular, other mount handles the torque. True-Stop disc brakes were integral from factory, pad relining is available in Denver, CO area. Most were removed with the advent of Spring Brakes, so spare discs are uncommon.

Ed

'37 GMC T-18 w/ DD 4-53T, RTO-610, 6231 aux., '95 GMC running gear, full disc brakes, power steering, 22.5 wheels and tires.
'47 GMC 1 ton w/ 302, NP-540, 4wd, full width Blazer front axle.
'54 GMC 630 w/ 503 gasser, 5 speed, ex fire truck, shortened WB 4', install 8' bed.
'55 GMC 370 w/270, 420 4 speed, grain, dump bed truck from ND. Works OK.