Hello-I have a 71 chevy pu with a big block 402 / with early model 427 closed chamber heads 101 cc xtreme energy cam 224-230@.50-515 - 520 lift somewhat mild for a BB - Perfomer RPM Air gap 750 Edelbrock carb - 2" full length headers- flowmasters.New Mallory HEI. Problem- I have got the static advance set @ 20' and no pinging 45' total and it seems it could take more - The truck noses down off the line and then goes-- any one have any ideas