Marked F873M Latch Blocks on centerline with 5/16 holes per plans Plans called for taping the blocks in place (which I did) then closing the door and engaging the locking pins, then rotating the block to find centerline and then drill a 1 1/16 inch deep mark. Instead I taped them in place, shut the door and engaged the locking pins, then marked the prepunched hole locations onto the latch blocks with blue marker. Removed the latch blocks and rotated the marked holes to the centerline then followed the plans of drilling #30 and final drilling #19 per plans. Countersunk holes for #8 attach screws and slightly chamfered the latching pin holes to aide in alignment. Installed blocks and latch pins went in place beautifully.
