Offhand it sounds like somebody changed the bracket at some point. As long as the unused hole is plugged with a screw or bolt, you'll probably be ok using only one bolt to hold the coil in place. There are 2 really important things to know about those two holes: 1. if either or both are left open, expect oil to constantly dribble out of them 2. if you use a bolt that is too long (you ideally want one that is 1/2" long or even 3/8" long (if you can find one that short)...you have a push rod sitting right almost square in front of those holes and you'll ruin either or both of those push rods if your bolt tightens into them. Image below shows it...yellow pointers are your coil bracket holes and pink are where your pushrods will be sitting. And to answer the question I'm certain is running through your little gray cells...no, I have no idea which "engineer" at GM came up with this scheme. Good luck!
Last edited by Jon G; 10/15/202111:37 PM. Reason: typo
~ Jon 1952 1/2 ton with 1959 235 | T5 with 3.07 rear end
