BBC - 1965-66 396 c.i.d. models have an oiling groove in the rear journal. The listed part numbered cams will not fit these models, so if you require a Camshaft with the oiling groove, please call us at 1-800-999-0853 or contact us, and we will assist you with placing an order. WARNING: Camshaft Optimized for use with a Melanized or Nitrided distributor Gear. Not compatible with cast or Steel Gears without similar surface treatments. Failure to utilize the proper distributor Gear will void all warranties and/or return policies.