[Captainfab]

There is absolutely no reason a short water pump won't fit a '79 small block. You can convert to a short water pump, but you will have to remove the '79 timing tab from the timing chain cover. Then you will need to move the TDC mark on the balancer, so that it lines up with a bolt on timing tab.

You can not mix and match brackets and pulleys between the short pump and the long pump.

Since you currently have the long water pump, why not just get the AC compressor and brackets for the long pump?

If you just want to have the alternator on the drivers side, most of the serpentine style accessory drives, have the alternator on the drivers side. But you will want to be sure to change your water pump to the correct one for the serpentine drive, as they are reverse rotation.