1971/72 Pontiac WK 400 ci. 4 Speed Standard Engine Block. Bore 4.12. Production date H31 August 3rd 1971. Block cast # 481988. Hot tanked and Magaflex No Cracks Good Core. Has two broken bolts. One water pump and one motor mount. See pictures. Block is drilled for 4 bolt caps. High nickel block. Service Replacement Date for Ram Air 2,3 or 4 Blocks. Block fits GTO, Firebird, LeMans, GT-37, T37, Grand Prix.