First off an edelbrock or afb 600 cfm carburetor is too small for a high performance motor unless you have the 383 standard motor than that carb is ok. Any "Old Motorhead" would know how to use a Timing Light and adjust the air inlets wth a screwdriver. You paid for what you do not know and as his income to support a family the charges are Fair. I don't suppose you would give your boss back half your salary just because you thought it didn't take all that time to fix whatever you do. Quit whining here.