Big Block Chevy block casting numbers Block Casting #'s Casting # Year CID Bore Description 3-76 427 4.250 4 bolt main, tall deck truck 3-86 454 4.250 3-76 454 4.250 3-90 454 4.250 3-85 454 4.250 3-84 427 4.250 4 bolt main, tall deck truck 3-88 366 3.935 Heavy duty with thick cylinder walls tall deck truck 4-84 427 4.250 4 bolt main, tall deck truck 14-87 454 4.250 4 bolt mains (casting number may also be 14015445) 3716323???? Splinter cell chaos theory rip. 396 4.094 2 & 4 bolt main with spin on oil filter 37-76 427 4.2 1966-67 396 4.094 2 bolt main with canister oil filter (rebored at factory?) 38-67 427 4.250 2 bolt main with canister oil filter (rebored at factory?) 38-66 396 4.094 4 bolt main with thick cylinder walls 38-67 366 3.935 Heavy duty with thick cylinder walls tall deck truck 38-67 427 4.250 2 or 4 bolt mai with thick cylinder walls 38 396 375, 4 bolt 39 396 4.094 325, 350, 375, 2&4 bolt 3902466????

Understanding Ford casting numbers is easy once you understand the numbering structure. Ford used a wide variety of structures for their part numbers and date codes. The majority of casting part numbers have 9 digits within 3 different groups and the first digit is the start of the part number.