Glad to hear you're enjoying it. I thought you would be impressed.
Makes very impressive power for the $$s spent.
The leaky timing cover/oil pan is repairable.
Some of the aftermarket timing covers have poor QC dimentions.
May need a new timing cover and seal.
break 'er in (keeping a eye on the oil level) and if the rear main seal does not leak, removing the oil pan is not nessessary to make the repair.
There are a few tricks to replaceing the timing cover and ensuring no leaks.
If your holley 600 is the generic #1850 there are a few good upgrades you can do to maximize performance. (rear jetting, power valve etc)