Description: The 428 Super Cobra Jet (also known as the 428SCJ) used the same top end, pistons and engine block as the 428 Cobra Jet but the crankshaft, connecting rods, and associated balancing were different. A nodular iron crankshaft casting # 1UA was used as well as heavier 427 "Le Mans" connecting rods with capscrews instead of bolts for greater durability. The heavier connecting rods and the removal of the centre counterweight on the stock 428 Cobra Jet crankshaft (1UA), required an external weight on the snout of the crankshaft for balancing. An engine oil cooler was standard equipment with the 428 Super Cobra Jet (later referred to as "Drag Pack") and 3.9 or 4.3 rear end gear ratios. In addition, there was a difference between the CJ and SCJ 428 cast aluminum pistons.[40] All of these changes to the engine components were made to provide greater reliability for engines expected to be raced and abused. Horsepower measurements at a street rpm level remained the same.[41] Horsepower measurements were not advertised for the higher rpm levels usually associated with racing. The 428 Super Cobra Jet engine was never offered with air conditioning from the factory due to the location of the included engine oil cooler.