Join Date: Sep 2000
Location: Washington, Michigan USA
The 1/2" hole in the pan rail below the fuel pump (which is not threaded) is a master machining locator - that's one of the points where pins on the precision conveyor pallet located the block during machining operations.
I see quite a few cars with the 3/8"x 3/4" bolt missing from the hole in the front that goes through to the fuel pump pushrod hole, and all of them show oil along the right side of the pan, motormount, starter, bellhousing, transmission, and crossmember.
Those two holes on both sides were there originally for the early passenger car front motormount brackets; the two on the right side weren't used again until the long water pump accessory drive A.I.R. pump bracket used them starting in '69. Without that combination, the through-hole should have a bolt (with thread sealer) in it, or you'll have an oil leak.
'69 Z28 Fathom Green