3.5 lbs pressure is at the limit a strom will tolerate.2-2 1/2 in more like it.How can you be running .045 in both carbs and then say you have .043 in the front one???? Should be .043 in both carbs. And power valves do NOT come in any kits that i know of. Except in OLD Sorensen kits. Stock PV's usually are too big running a 2x2. most run #67-#68 in them. Your running too much gas through them your over carbed. OMO ken ct.
If the accelerator pumps have not been modified for dual carb use, that is where I would look. The article by Barney Navarro shows how you drill a small hole in the pump setup to keep the gas level lower in the pumps so they don't give the engine to much gas. Think about it, the gas from 2 accelerator pumps when the engine originally only had pone. Too much!
Ted,first thing they blame is the carbs when somethings wrong. ken ct.