A "Brownie" is slang for a Brown-Lipe auxiliary transmission that mounts on crossmembers between the main transmission and the rear end with two short driveshafts. There is a separate shifter in the cab. Other auxiliaries are made by Spicer, Dana, and a few other manufacturers. Most of them have an underdrive, direct, and overdrive ratio, so each main box gear has three ratios available. When the engine starts to lug down in direct drive, you can shift down a little instead of dropping a whole gear. It's much simpler to drop half a gear and keep the engine in the right torque band, with 12 forward speeds instead of 4 to pick from. You'll also have 3 reverse ratios.
Yes, car and truck 350's are basically the same, except for the 4 bolt main bearing engines used in medium duty trucks and factory hot rods.
Jerry
