When I jump on the gas from shifting I have a slight lean spot or surge. The Holley power valve video says cut vacuum pressure in half and thats power valve size. Vacuum is 20 I did run a 6.5 and 8.5 I think numbers were hard to read. Now 9.5 running better than before but guzzles gas.
I did start out with a 51 main jet ran strong but had a very bad lean stumble when getting on gas from shifting. I increased main jets till stumble was hardly noticable but still there.
Ive had as high as 160 no stumble but doesn't have the performance motor had with lower lean jetting sounded like it ran better.
