Got a 'good' carb what was 'never' rebuilt for my 380 sbc Chev in my S10 truck! When I took it apart, it didn't have a spring under the power valve and the float level was approx. .400 so I raised it & put in a kit. I had a power spring kit and stalled the longest spring as the other two were the same length as another carb that I had even though the power valve had a much long pin coming out of it than my other carb. When started it it acted as though there was a fuel starving problem. Wouldn't keep running with steady throttle except when continued pumping the accelerator pump. I lowered the float level and it helped, but then started surging like fuel starvation or a vacuum problem. The engine has a big cam, so could the long pv spring be having a tug of war with the manifold vacuum making it surge? I checked the gaskets to make sure I hadn't installed the wrong one. Any assistance would be appreciated.
