cadddy engine question

Got a '52 cadillac club coupe with a late 50's cad motor. some genius/thief has ground serial numbers on head to a mirror finish. has the valve covers in standard block letters instead of the nicer cursive ones. so im guessing it's a 365 or 390 but thats all i'm doin is guessing. you guys know what year they changed to script on the valve covers in the late 50's or even better how i can tell the difference in a 365 and 390?

 

on the back of the block, top left side. There is another series of numbers probably starting with a 4. Let me know what numbers you have and I could tell you what you have

 

the earily block was a shelf type bell housing like early flat head fords( flywheel covered by block). later caddys had open type bell housing like a sbc.( exposed flywheel). i think the split was 55 or 56 365 engines for the bell housing and the the valve covers. also a very quick way to tell if it is a late block look to see if it has an oil filter on the back passenger sid eof the block. late 365 and all 390 had and oil filter on a bolt on adapter on the block and twist on modern type oil filter. the vin number was on the front edge of the block just in front on the valley pan. the first two number will be the year.

NOTHING LACKIN WHEN YOUR CADILLACIN !!!!

 

1955 was still a 331 but was the first year that did not have the extended bell housing.

I would start with the block style first and go from there.