G'morning Sarge! I'm pretty sure it was closer to 700+ while I was adjusting last weekend - it was NOT less than 650. Bob at TPI asked same thing yesterday when I was placing an order for a dizzy tune up parts (cap, rotor, points, conds). Also, I had the vacuum line attached while setting lean low idle - and that might have given me an improper setup. Bob suggested removing it, re-setting timing first before setting low lean idle.
Hey brother, I've got a brand new Trollhole Dizzy sitting in the garage awaiting installation... Wanna install it and see if it improves anything for you? Just a thought.