I just picked up a '72 455 for my Cutlass, I was told it came out of an Olds 98. The block numbers check out with the typical large F atop the timing chain, the heads were Ga's, matching the '72. I pulled the timing cover to find the gears are set at 12 o'clock for both cam & crank when at #1TDC. My manual shows them at 6 & 12, for cam and crank respectively. Having just done a Ford, its also the same, but I checked the Pontiac manual which shows them at 12 & 12. If they are supposed to be at 6 & 12, I can only figure the distributor was taken out and re-installed at 180 degrees, since the 6 and 1 are symetrical. Putting the marks at 6 & 12, the distributor rotor is pointing to #6. Anyone run into this before rebuilding an Olds 455. Should I just pull the gears and replace them as they were taken off ? Thanks in advance for the help.