91 Grand Am SE Quad 4 woes

I purchased a 1991 Pontiac Grand Am SE with 133K mi. A very nice little car. The engine will not turn over by using any means. I have worked on the 2.5 Tech 4 and have extensive experience working on a 4.5 Cadillac engine (replaced heads & head gaskets), so needless to say I have good mechanical experience. I am wondering what I can do with this engine to see if I need a whole new engine or merely a head. I have a 1991 Grand Am LE with 86K mi that has been sitting for quite some time, but the engine will turn over. Any pointers on where to start? Thanks -Brock