Some emgines have the oil pump in the fromt cover. Gat a manual on your car from a parts store or from AUTOREPAIR2000.COM
Remove engine oil pan
It is located in the oil pan
you have to drop the oil pan.
Drop the oil pan
Of course, there is no other way to get at the pump.
how to replace oil pump on 1994 z28
Drain the oil from your 1993 Chevy oil pan. Remove the oil pan retaining bolts. Remove the oil pump retaining bolts. Reverse the process to install the new oil pump.
4.5 quarts with a new filter.
You need to remove the engine and then the oil pan. The oil pump is easily replaced with oil pan removed.
its a wrap get an new engine
Read what it says on the OIL filler cap....
Bstuff.com should have the info you are looking for.