need some help with my 2001 malibu!!!

ok so i have a 2001 malibu 3.1L and i cant get it started...my dad was driving it and it just died on him...we got it towed home and i started taking it apart...found blown head gaskets and the timing chain was loose...i took the heads to a machine shop got them back the next day...they did the valves and resurface i put everything back on along with a new timing chain...now my problem is that i cant get my car started all it does is turn over...i checked everything and i cant find anything wrong or anything i missed...when i put the new timing chain on i set the bottom crank gear at 12 o'clock and the top cam gear at 6 o'clock thats how i read they were supposed to be set...when they were set like that the #1 piston would never be at TDC when the marks aligned...im not sure if i did that right...when the timing marks are aligned the #3 piston is a TDC...ok so i checked the spark yesterday and the spark is really weak...i took the coil packs off with the module took them to autozone and had them tested and they said that they were good...now i dont know whats causing the weak spark? spark plugs or wires maybe? or making one of the cennections that go to the module? there was a wire i found that one end plugs into the module and the other end plugs into the block...dont know what the plug on the side of the block is? some kinda sensor maybe? well any help i get would be great thanks im gonna see if i can try and figure it out and be on here on and off