I have what appears to be a 427 Corvette motor, but I am no for sure. I have been trying to find out when this block was made and what it came out of. The casting code on the block is 3989854. Any information on what this block is would be greatly appreciated.

My info shows this to be a 402 (396) block used in passenger cars, chevelles, camaros, vettes from 1970 through 1972. In 1970 was both 2 and 4 bolt main, in 71, 72 only came in 2 bolt configuration. A casting date and the information from the front pad would be helpful.

I have an "854" block dated A 30 70, with a code of CKO. Mine is a 4 bolt main out of a '70 Camaro.
Rick