Are you absolutely SURE it is related to the HEI? It wasn't draining before? I installed an HEI and "thought" it might be causing the battery to drain over a few days. Of course prior to that I always disconnected the battery. ANYWAY, it turned out to be the voltage regulator. I replaced the original internally regulated alternator and external voltage regulator with a 140amp CS130 internally regulated alternator. Problem solved....NO more battery drain. I haven't driven the car around the block in over a month went out last night and turned the key and she fired with up.
