I read what CP & Tod said about the primaries & drilling. I had the same problem w/a 850 DP on a BBC. I had a internet documentary about this very thing & I drilled 1/8" holes in the primaries (one per) in the corners farthest from the idle transfer slots. This helped a great deal. Later, I replaced the carb with a QF/HP which has secondary butterfly/adjustments which does the same thing. I want to note the obvious however: if you are in a shop, you are going to get burning eyes & a rich smell anyways while tuning/running on a HP motor. In addition, I also run a primary PV. although my dist. is manual, I run 2 to 2.5 steps lower than my inches of vac at idle which works good for me. Good Luck!! Scooter