I recently had a 96 cavalier, 2.2l 5-spd gave to me that had a broken timing chain. When we put the new chain on, it would try to start, but wouldnt. We checked the compression on each cylinder. One had 130psi, one had 45psi, the other two had less than five. We then hooked an air hose to each cylinder (after loosening the rocker arms) and each time air came out of the exhaust. I know that I have valve problems, and I will need a new head(which I have), but is the block good, bad, or will I only know after I pull the head off?

Are you sure its timed right? mabye when the chain went it screwed up some valves... try changing the head, the block should still be ok. are you putting a new head or a rebuilt? if rebuilt make sure it was milled right, because i have seen what happens when they aren't, you'll have head gasket problems very soon.