compresion test of 125lb. Cam question

When I first installed the cam I used the 4* offset key, because the 2* fell in the oil pan and I couldn't fish it out with a magnet. I was so rich running it was like steam from the exhaust. So I ran the stock key @ 110 centerline. That's what ran 108.7 Mph.
When I recently replaced the oil pan gasket and a HV Melling oil pump, I got out the 2* and the centerline is now 108*.
Maybe there was something else wrong I didn't notice w/4* advance @ 106 C.Line. Like the 650 Double pumper was too small and ran rich at idle. Possible? That good working 650dp did the same rich thing when used on the 440. I went to the 780 Vac and it still ran 108mph, back then.
So I am wary to advance it and waste the time. I could replace it for the same amount work.
My limited practical experience is why all the guessing. The Cloyes will allow 4* more advance. Should I try that?