The Stovebolt Site Forums The Shop Area Engine Shop Holley 1908 float/ carb problem on GMC 270

Hi, After about a year of my '56 GMC model 150 sitting with a damaged exhaust valve on the 270 small port, I have had the valve job done, got it all together, and when I used an electric pump to prime the carb, the fuel just gushed out the little 3/16" angled venturi? tube at the top of the carb throat. The elec pump (which I have used before with no problem) puts out a little less than 2 psi. Too much? I adjusted the float level to no avail, now I am wondering what my next step is. The carb was rebuilt last June, and it ran for two weeks before I blew up the muffler. (you may remember that) The float works if I hold it up with the cover off. I have the carb on a tray with a long fuel line so no more gas in the engine.