Found out where the power valve is..gotta love the internet.
Carburetor Power Valves Video - Holley Carb Tuning DVD - YouTube
Hopefully it's just the gasket on the power valve that blew..I'll need to check the vaccume or follow some of the tips from the video to see if it's the valve that went out. Then I've gotta get into the carb to see the Valve size etc anyhow..another learning experience.
Thanks guys,
Have a good day..
Lee