Pre-62 A, B, Hemi and poly motors all had extended flange cranks and aluminum bellhousings. This doesn't include the early Chrysler Hemis that had the upper bellhousing that was actually part of the block casting. (Edit - some if not all fluid drive semi-automatic trannies had cast iron bellhousings; AFAIK, all pre-62 Torqueflite and Powerflite trannies had aluminum bellhousings)
My 56 Plymouth, 277 poly (basically a 318 poly with shorter stroke and smaller bore) has an aluminum plate bolted to the block, aluminum bellhousing bolted to that aluminum plate, and a 2-speed Powerflite with a cast iron main case and aluminum extension housing. Late in the 56 model year, Powerflites got aluminum cases.
56 was the first year for the three-speed Torqueflite (and, yes, that's what it was called). That year only available in Chryslers and Imperials, it became available across the board in 57. It bolted to the aluminum bellhousing, had a cast iron case from its introduction through the last year in 61. Not sure if all motors had the aluminum adapter plate bolted to the block.
In all these early Powerflites and Torqueflites, the torque converter bolted to the crank with eight bolts. Then the bellhousing is installed over that, and then the trans input shaft is carefully inserted into the torque converter as the transmission is slid into place.
The Powerflite in my 56 is air cooled, so has no tranny lines to the radiator. Instead, there are fins on the torque converter acting as fans, and the bellhousing has large screened areas to allow the flow of air across the converter Not sure if any Torqueflites are air cooled. Some Powerflites I believe are water cooled.
62 was the first year for the aluminum 727 Torqueflite, in the "modern" configuration of bellhousing integral with the main transmission case, torque converter slips into the trans, then trans is bolted to the motor, then the converter is bolted to the flex plate, which is bolted to the crank. Powerflite was dropped for 62. Slant sixes got aluminum 904 Torqueflite trans beginning in 1960.
1958 was the first year for the B big block, in 350 and 361 inch versions. 383 was introduced in 59, as was the 413 - available at first only in Chrysler New Yorkers and 300s. (Edit - and Imperials)
A 413 with an aluminum bellhousing and a torque converter bolted to the crank has to be a 59, 60 or 61.
FYI, I have a 64 Chrysler 413 engine hooked up to a 62 Chrysler 300 non-letter car aluminum Torqueflite in my 59 Dodge, hooked up to the original 59 Torqueflite pushbuttons. The aluminum Torqueflite is stronger and lighter than the old cast iron Torqueflite.
The rear of the pre-62 318 poly blocks is different than their later cousins, making it difficult if not impossible to swap cranks and run the later trans. Not sure about the big blocks.