gtobob67,
67Lemons,
My 73 455 has the same couple of chamfers. My cam is ground with the top of the lobes .007” under the bearing journal. If they were at the same height as the journal the lifter fill holes still would not have came out the top, other blocks could be different and need verified. The lobes can’t be taller as the cam couldn’t be installed
The biggest issue is the lifter oil bad dropping below the boss on the base circle. As the lift gets bigger the lifter drops lower in the bore on the base circle.
If you can find out the base circle dimension and the lobe lift you can get a 95% chance of figuring it out before buying.
Pontiac cam journal specs are 1.8987 to 1. 8997. Use 1.899 for the diameter.
Lobe below journal = Journal diameter- ((2 x lobe lift) + base circle)
If you run the Howard’s/Gaterman lifters you will not have an issue with the lifter out the top on any block. The tops of the bore/chamfer would have to be an 1/8” lower than I have ever seen.
The only caveat is the modification ls to the oil feed galley.
The biggest area of concern is dropping too low in the bore.
Thanks,
Stuart “Stan” Landreth
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