Front cover r&r

[Paul]

I got a terrible oil leak somewhere around front cover or brass oil pressure block or maybe PTE adapter cover. Thinking about taking off aftermarket cover and putting on used GM cover. Question is isn't there some of the cover bolts that may leak (go thru into the block) if not sealed up with thread sealer? I wrapped shop towels and some duct tape around the PTE plate and front cover and ran the car to eliminate possible VC leak and it stopped the oil blowing up on the underside of the header pipe like it was doing so it has to be front cover, brass block or sending unit for oil pressure, or maybe PTE screw on cover. Drainback tube gasket is okay and dry..used the GM black thick one's on that. Also don't the oil pan need to be dropped to do the cover? Thanks in advance.