EXCELENT CONDITION, PERFECT TEETH. CENTER BORE ON FLYWHEEL IS 2 1/2", HOLE PATTERN IS 3.640". CAME OFF OF A 250 CHEVY CRANK IN A 250 OHC 6 PONTIAC.  WHEN I SOLD ENGINE TO A GUY WHO WAS GOING TO RUN AN AUTOMATIC TRANS.  WILL BOLT TO A 250 PONTIAC OHC 6, BUT FLY WHEEL BOS DIAMETERS ARE DIFFERENT DIAMETERS. 50 MILES WEST OF LAS VEGAS.