It just occurred to me that they may have raised the engine for alternator clearance at the front frame rail pinch weld when using the car front cover.
Could be. I haven't tried an alternator on the motor yet to see.
I was guessing they did it to fit a bigger oil pan. The stock A-Body pan is like 3 or 4 quarts, this one is 6 quarts and hangs below the k-frame about 1/2" even with the motor sitting up.