I'm no help, but looking to learn.
I can say when we replaced the top end in our 273, that I installed crank gear wrong. Like Max mentioned ours had 3 keyway choices and of course I picked the wrong one lol. A member here Badsport and others here helped solve my problem. Thankfully discovered the issue while engine was on stand. Turned over by hand and it locked up...pulled valve cover and 2 push rods were bent.
Good luck!
Was this an orig stock engine? Or apart previously and worked on?
