1970 Chevelle 396 HEI Ignition No Spark

If the vac adv was hooked up, the p/up wires flex & will eventually break. Check the p/up wires [ disconnected from module ]; they should measure several hundred ohms. Wiggle the wires while testing.
With HEI, the body of the dist has to be grounded to produce a spark [ unlike Chrys elec ign ]. Make sure the dist clamp is making good electrical contact with the dist flange.