I have two vac ports at the rear small fitting for vac sig for efi computer, lg 3/8 for pwr brakes or ? This may work for pcv?
Also, too late, I found a thread spelling out the shortcommings of the early shelby blocks, one of which was
oil drain holes at rear main being too small, / being covered by pan flange and gaskets as one cause of rear main seal leaks
My block is sn 56, so very early.