This motor is in a 1983 Oldsmobile 98 regency. What type of engine is it? Its not the original. Its a v8 that valve cover only is supposed to have 5 bolts in it..

 

It's a 73-later Oldsmobile engine but not enough clues for us to determine year or displacement.

Take a picture of the "shelf" between the water pump and intake manifold at top front of the engine. Looks pretty greasy, hit it with some brake or carb cleaner so we can see the numbers and/or letters cast into the block.

 

The later Olds V-8 engines used only 5 valve cover bolts, but the heads and valve covers had the "shape" for the traditional 10, with just 5 actually being used. This means an earlier 10 hole valve cover can be used on a later head with just the 5 bolt holes.

 

This casting number will tell you what the displacement is.