[A Snake]

I'm not the carb expert I wish I were, but after reading the entire thread, I have to ask BEB and the helpful group a couple of questions. It may be that the carb is being tinkered when it really wasn't the problem at all.

MrFixit, you can jump all over me if you want.

1. Has any consideration been given to the possibility that the carb is too big for the application? Run the displacement X rpm @ 80% Volumetric efficiency. Go to the Holley site and check the numbers to see what should be on the engine. Without looking, I'm guessing a 650 would be more than plenty. Remember, you can use more carb if it has vacuum secondaries. Mechanical carbs are pretty fussy that way.

2. That mild cam makes a ton of vacuum at idle, and up into the 2500-3000rpm range so there should not be any problem with vacuum signal at all.

3. Playing with the accelerator pump cams is fun if you're working on a race car. As the carbs come out of the box, they are pretty well dialed in for a wide variety of applications other than all out racing. Again, check carb size.

4. Last, I would strongly suggest taking the distributor out and having it set up on a distributor machine. Playing with springs is asking for troubles such as burnt valves and broken rings. It doesn't matter what a book says about a certain spring doing a certain thing. The acid test is how it actually performs in YOUR distributor. You should have about 38 degrees of total advance and DEPENDING on compression, 10- 12 degrees initial at idle, assuming the cam is degree'd straight up. This all assumes a comp. ration of between 9 and 10:1.

Add all of this together and you may find that all of the monkey fiddling wasn't needed at all.

Hope this adds some food for thought.

Al