I just went out today and bought a vac. gauge to try and finely tune this darn 600cfm edelbrock on my 310 c.i. L69. Here are the specs on my cam: 442/465- 204/214 duration. I am getting 15 inches of pressure at idle.

I hear that for the best performance you should try to get the maximum pressure at idle. It seems that no matter how hard i try, I can't get the needle to move more than a half inch. By then the car wants to stall anyway. What gives???

Also, is it normal for the needle to hop a bit ( like half an inch of press.) at idle as the cam lopes??? Or should it be 100% steady????

I checked for leaks, none present. Checked all bolts for leakage, none. A buddy of mine suggested that I check the vac. canister to see if it is faulty. The car will idle where I want it to when I first start the car but after I run it for a while, it rises in rpm to like 1200. So I think the advance on the distributor could be malfunctioning a bit.

I really need my questions answered on the Vacuum gauge though.

 

Youre on the right track..I know everyone has different ways of doing the same thing, but start by setting the timing before ANY mods or adjustments to the carb. Hook the gauge to manifold vacuum, and set the idle to where the engine is barely running, 500 rpm or so. The turn the mixture screws equal amounts in and or out until you get the highest readings. Once you get the highest reading, hook your hoses back up and set the idle back up to your prefered idle. I wouldnt be concerned about a bouncing needle unless it is more than 3 inches or so in either direction. I have found that a small fluctuation is normal.

Hope that helps you out....but that is just my method.