I'm certainly no expert on this, but over the years I have heard of a deeper truck housing also, but was told it was in big trucks with a heavier 4 speed ******.
I do know that they made a stamped steel housing and two different cast housings for 49 to 53 cars. One is a complete surround housing that uses a stamped steel TO bearing arm/fork and the other was open on the bottom with a tin cover for the bottom and used a cross shaft throw out bearing fork.
We ran some 64 & up top loaders behind flatties and the hole in the complete surround housings, both stamped and cast, for the front bearing retainer would only accept top loaders with the 1 1/16th shaft and retainer while the open bottom one would accept the top loaders with the 1 3/8th shaft and retainer. Two different sized retainer holes.
We got some of these housings (open bottom) out of U.S. mfgd cars, and one of them out of Canadian mfgd 1954 flattie powered Meteor. One of them also came out of a 48 F-1 truck, that I thought at the time someone had put a 49 - 53 engine in, but was told that the 48 F-1 came with it from the factory. I don't know if any of the other cars we got these housings out of had been subjected to engine or other changes or not as most of them came from a "wrecking yard" that all of the (to put it nicely, as this is not what most people called us) younger generation of vehicle modifiers used.