I have run a 750 vacuum secondaries on my stock 383 extensively. I have also tried a 750 double pumper on it as well to try out this myth. I can say with great certainty that there is NO difference in performance between the 2. Now with that said the DP did require a good amount of tuning to eliminate the bog associated with the sudden opening of the secondaries. The Vacuum also needed a fair amount of tuning to achieve its best as well which included the lightest spring, which will open the secondaries quickest. The DP was way snappier on the street. One interesting side note is that the Vacuum carb did 60' better. I have also played with the carbs on one of the small block I have dynoed in the past and at 400hp level the vacuum carb fell way short (25hp). One of the things I tried in the dyno cell is to run the engine and make a pull. When the engine starts to accelerate I go out into the dyno cell and manually check to see if the secondaries are open. They were not open and I was able to regain the 25hp by reaching out and holding open the secondaries by hand. I think this is a myth started by a few cars that werent tuned right. :soap:
Okay now thats over with, lets get back to your problem. I would start with the accelerator pump squirters. Start with one end, probably the secondaries, move down a size in squirter until it stops bogging or gets worse. If its gets worse at the first change you went the wrong way, so put a bigger one in. Once you find the sweet spot move on to the primaries. Same progression. After all that is done make sure you have .030 clearance between the pump arms on the accelerator pump and the lever that comes from the linkage. Once thats set and the bog continues move on to accelerator pump cams found bolted onto the throttle shaft. This can be a long drawn out process but once its right hang on!
