I'm trying to think through the logic of making those changes to the carb. No, have not done a compression check since it is a new (2000 miles) engine. The vacuum at low speed is so low & erratic that the PV would switch on and off if I went to a higher # valve. The carb was born with a 6.5, and the engine was drowning at low speeds. I put in a 3.5 and that helped a lot. Before changing the PV, I did drop the main jets from 73 to 68. Had a definite lean condition, so went up 2 sizes and that eliminated that (at 70 now).