95 roadmaster leaking engine oil can it be oil sending unit?

On your engine most likely close to the oil filter . Have a close look around where the oil filter attaches to the engine.

which seal? front crankshaft seal,rear crankshaft seal,oil pan seal, there are several more.

There is a huge difference in price and oppinion between your two mechanics.If I may suggest,go with the oil sender unit and hope this is it because replacing a main seal is going to cost you a lot more money .Ask the mechanic to put the car up on the hoist and show you the leaking sender unit.They should be willing to do this for you.Use your own judgement and good luck

they are usually located on the side of the block by the oil filter

Look up overhead above the sending unit for any oil that maybe dripping from above,makeing you think it's the sending unit leaking. If not then you may use a little thread sealer to seal the leak. Also check to see if the sending unit is loose and the threads may not be the same as the old unit you removed (metric/standard/pipe) Hope this will help you.

clean engine with degreaser then run it to locate the exact location for leak

check the ignition coil

Fuel Pump RELAY & FUSE CHECKED & DO you Have POWER "TO" Fuel Pump ? ALSO OIL Sending Unit Supplys the GROUND To Fuel Pump , This is A Saftey FEATURE that Shuts Down Fuel If ENGINE Looses OIL PRESSURE . And If This OIL Sending Unit or also Called (OIL PRESSURE SENSOR) << If It FAILS it WILL Cause What Seems Like A Fue Pump Problem But Is Rally Just The Sensor that is BAD. HOPE this Sheds Light on Your Problem !

A "spray" is not a leak.. That sounds more a like an Oil Sending Unit .. Peep near the oil filter and look for a screw-in thingy with wires ( or wire ) goin to it.. Its unther the car near the front of the engine withing 6 inches of the oil filter

First check your oil level if it is full take the oil sending unit out and install a pressure gauge to check you oil pressure.Compare your readings to the correct specs for that vehicle.If the pressure is good and the plug that connects to the sending unit has one wire only,do as follows.Take the plug loose from the sending unit,turn the key on and take a paper clip or other item and ground the wire to a good engine ground.If the light illuminates while it is grounded,the circuit and the light itself are good.Do not do this test if there is more than one wire going to the plug!!!I You could just replace the sending unit if you dont wont to test everything..The sending unit is cheap...Good Luck...