Ok so I have several oil leaks on my LT1. It looks like somewhere in the front, either the opti and or the water pump seals. Also the rear, definitely the line bolted on the passenger side head, probably the intake and definitely the low oil sender. I also need to replace the ac compressor and evaporator. There is about 70k on the car. Do you guys recommend fixing one at a time or just pulling the engine and doing everything?