Brain malfunction, 2nd engine no. should be 7294440, got mixed up with the hydramatic no. that is P52-50444X. Sorry about that.

If these are "wide block" 6's , 232-262 have casting number, 304299 = 1951 -1953
308 has casting number 304539 = 1951-1953
232-262 for 1954 have casting number 310110
308 for 1954 has casting number 310111
308 for 1955 and 56 has casting number 532500
Number is cast on the crankcase below the distributor.

222153 came out of a 1953 Hudson built in Feb. 1953. I don't have a model/body breakdown. 729440 came out of a 1954 Hudson built in Feb. 1954. This one is probably a 1954 Hornet (308 engine) - that would come from the 1st number, 7.

Hudsonly,
Alex B

Since he didn't specify what era of engine he's got, I read them as '37 Super Terraplane (model 72) and '42 Commodore Six (22), both "splashers", of course, but would have the distributors in the side and rear, respectively.
F

Serial number blocks for 1937 only go to (Super Terraplane) 19907 and 1942 Commodore 6, Model 22, only go to 41232. I see your thinking that the first digits are part of the serial number - they aren't. In both years the entire block wouldn't be used. Many people think that production is obtained by subtracting the starting number from the ending number - it doesn't work. Especially in 1942 when only 5,396 cars were shipped (as opposed to produced) from the factory due to conversion to war production in Feb, 1942 and car production ceased..
Hudsonly,
Alex B

Thanks for the id of the engines, I had checked the casting numbers and they came back , the early one was cast '52-'53 and the later one was cast '54. Nice to know that the one was used in '56. These are both 308 engines. I am going to rebuild one, and was trying to decide on which one to inspect first. I guess that they used the 1954 castings all the way to 1956. Did they machine the engines differently for the later year? The '56 engine had an Isky cam in it.
Thanks again
Cal

As is too often the case, I stand erected, however I'm curious as to why my '42 Super Six (model 21) has s/n [i]21[/i]22907 if that's not what the first two digits signify? Also a '42 C-8 with s/n 24****? That can't be coincidence.
Hopefully, Mr. Parsons will throw-in some more info.
F

Hopefully my previous post clarifies the situation, if not please ask , and I will try to answer.
Just for the record, my 1942 Super Six # is 2112390. interesting to know who else owns a '42.