I don`t recall the casting number on it, but I have a similar looking bellhousing behind the 428 in my 59 2 door sedan. The casting date was for a late 1960 or early 61 as I recall. I prefer the later style clutch forks with the flat leaf retaining spring, so I replaced the pivot fulcrum and clutch fork with McLeod pieces, which works fine with the 59s factory mechanical clutch linkage. I also used a new McLeod steel flywheel and 11" Long Style "Street Pro" clutch kit. I am using a small block wide ratio Toploader, and had to use the inside mounting holes, as the early only has the narrow pattern. Biggest concern is these early bellhousings have a smaller hole for the transmissions front bearing retainer. I had 3 options, 1 is to find a 1964 only Toploader bearing retainer, 2nd is to have your existing retaining machined down to the smaller diameter, or finally, do as I did, have the bellhousings hole opened up to the 65& newer size. I went that route so than if needed, any other Toploader would fit. Although these early bells are designed to use the early long shaft "follow Thru" starter motor, that did not use a steel block plate between the engine block and bellhousing, and had a smaller flywheel, I used the later 184 tooth flywheel, and short nose starter, and a block plate, and it starts up great with no funny noises.