I have a edelbrock preformer carb on top of my 350 and I'm having LOTS of trouble setting the fule/air ratio. I have tried using my vaccume guage but am still having problems. Basicly it's because i have a cam with a 272 durration and a 454 lift. When i hook up the vaccume guage i dont get a steady base reading. The needle jumps all over when the lope hits. As i cant get a steady base reading i am having alot of trouble adjusting the ratio. I thought i could possibly get a fuel'air ratio guage and a o2 sensor and rig something up? Any help at all would be greatly appreciated

 

What you may want to do is try to bump the timing up a little bit to steady the idle some, bring the idle up a little bit so it smooths out. tune it there, then work your way down


if it's idleling too hard to tune at 500rpm, and 10 degrees timing, bump it up to 800 rpm, and a little more timing till she smooths out some, the vacuum will level off then you can bring the idle down little by little and the timing will go with it.