Mopar used the same casting numbers on the 440 blocks from 1966 to late 1971 blocks. Starting in early 1972 they changed the casting numbers on the 440 passenger car motors only, HD, industrial and marine motors weren't changed shruggy
The main thing you need to know about is if that motor is internally balanced or externally balanced scope If the seller doesn't know see if the crankshaft balancer has a oblong external ring around it or not, if it does it means it is externally balanced and that balancer should say for 440 motors cast into it scope
If it doesn't have a balancer like that and does NOT shake when running up through 5000 RPM then it is probably internally balanced, up The bad thing about externally balanced Mopar V8 is Mopar used external weights on both ends of the crankshaft on the flywheel or converter with weights welded onto the converters whiney
Please let us know what you find out work

Last edited by Cab_Burge; 04/15/18 08:00 PM.
Mr.Cab Racing and winning with Mopars since 1964. (Old F--t, Huh)