ok guys so I confirmed that my secoundaries are not coming open all the way.

 

If you have vacuum secondaries then they should be opening up as much as the engine needs them to. Im not sure how they're calibrated but if you have a serious problem elsewhere the combo that's hurting your power, your secondaries are going exhibit the same behavior (assuming they're calibrated correctly) as they are now. If the engine can only breathe so much air, then the secondaries are only going to open so much. And of course, breathing more air is the idea.

 

I have a bigger cam which creates less vaccum then a stock motor. I can change the spring in the diofram on the carb to get the secoundaries open all the way I was just wondering how much hp difference that could make.

 

Some, not huge amounts. I usually replace the stock plain color spring with the yellow one as a starting point.

Remember the vacuum secondary system runs on venturi vacuum which has little to do with manifold vacuum. It's a pure total-airflow-through-the-carb amount of vacuum. More airflow, more venturi vacuum, more secondary opening.