Drilling Holes In Carb Throttle Plate Blades

Newbomb Turk said
Most likely not.

What is your idle timing? Start with that.

BTW, how far does the engine drop from P to D?

It drops 600 rpm now. Something changed. I had it to 200 rpm differential. Now at 1200 rpm in park/N then in gear about 700 and it shakes and runs very rough and I hear possibly detonation. It’s real bad. Vacuum drops from 11 Hg to 7Hg.