Edelbrock Carburetor Tuning

dICKj said

It's a new Edlebrock Model 1405 600cfm 4bbl on a new Weiand model 8007 dual plane manifold on a stock 1974 Duster 318 (except for dual exhausts).

Click to expand...

On my 318 the 600cfm stock squirt nozzle was too small I upgraded to the 43 size nozzle bog went away although my 318 was not stock, But in your case on the pump shot arm move it to the bottom hole see if the flat spot goes away. Also I would recommend using the silver springs to match your stock vacuum signal on the stock 318.