Engine will not start after changing head gasket

I just replaced the head gaskets on my 1993 Dodge Dakota (3.9l v6). After putting everything back together the truck will not start. It sounds like it is turning over but without any compression in the cylinders. While turning over, there is a loud screeching noise coming from the back of the engine like something is spinning but not catching. While changing the head gasket I did take the distributor cap and rotor off but that was it, so I am not thinking it has anything to do with the timing, but I am not 100% sure. The spark plug wires have all been put back in the original place. I can smell a little gas and I can hear the fuel pump kick on when first switching on the key. What else might I be missing, or anything I overlooked. I am staying at my uncles house 2 hrs away from home until I can fix this, and I am running out of ideas on what is wrong.