You have reduced your compression considerably with the camel hump heads. They're 64 CC's, and the heads you removed were probably 58 CC units. The 283 doesn't need 1.94" valves unless you're planning to spend a lot of time above 6,000 RPM. The low-end torque will just about go away with that setup, and a 283 has very little torque to begin with.
It sounds like there's a capacitor somewhere in the ignition system that's got an open bleeder resistor, and it's staying charged after the ignition switch is turned off. You'll probably need to get a warranty replacement on the ignitor, or use a regular GM HEI unit instead of trying to modify the original distributor.
Jerry
