Here is a 409 engine for a 1962 Impala. The block casting is a 3788068 dated November 25th, 1961. The heads castings are 3914690 dated November 14th, 1961 and March 15th, 1962. It was a Mickey Thompson cross ram intake called Power Ram casting 3746409. The carburetors have been modified for better flow and are etched JSR with a date stamp of 6-91. The passenger side carb base has a crack near one of the mounting studs. The crank is a 454 casting 7416. I don't know the specs on the cam but it has roller lifters. The oil pan has been deepened. The flywheel is sfi rated with ARP, except one, bolts. It also includes a pair of Stahl headers. I was told this motor was in a 1962 Impala paired with a powerglide that ran low 11s.