Gas line routing

That is a new one for me... an HEI causing pinging. Here is what could be happening:
- HEI's create a hotter version of what is called the 'spark kernal' (the initial phase of combustion, from which all the rest of the combustion spreads)
- A hotter spark kernal will cause the initial phases of the combustion process in the chamber to move along faster.... In that aspect, it is somewhat like more timing advance in the system.
- The /6 combustion chamber is not the best for too much timing advance.
- So you may have to retard the initial timing a few degrees now. Where is it set now?

Before HEI 5 degree before TDC, with 28 of centrifugal never revved it over 4,000 rpm, total of 33 degrees. Using autolite 66 plugs with washes on. After HEI conversion 2 degrees before TDC, with 30 of centrifugal also never revved it over 4,000 rpm, for a total of 32 degrees. After this it was ping city. Tried the fuel sock over fuel line helped some. Then changed to NGK plugs 1990 dodge dakota 4 cylinder with 0.045" gap. Zero ping even at 70 mph going up hills. Timing not changed, no vacuum advance hooked on any test, same fuel, only changed what was listed above.