750 Edelbrock issue

I haven't checked it but I remember setting it at 12 BTDC. It starts up nice doesn't fight the starter etc. I remember it didn't like the 5 BTDC book spec setting.

I was setting timing about a year ago I could go back over it.

If all it has is 12, I bet that's probably the whole issue. Pull about 16-18 in it and see how it is then. You'll likely have to adjust the idle.