Correct Spark Plug Gap & Timing

I have a 1971 Impala Convertible with 350 motor, new Edelbrock Performer 600 cfm carb w/electric choke and Edelbrock Intake. I just converted to the Accel HEI distributor. My question is, what are the best spark plugs to use and correct gap? I have been using AC Delco plugs. The spec calls for 0.035 but since Ive upgraded Im thinking it should be more like 0.040-0.045 for my gap? Need a little input.  Should be an easy one!
 
Thanks.

that sounds good. run about 12in and around 36 t timing. hope this helps