I just replaced the condenser, radiator line, the A/C line to firewall, & the oil pressure sender. To get all of this done, I removed the battery, radiator, fan shroud, overflow bottle, dryer, wind deflector, etc.. Did I forget to reconnect something?

The car started fine before I took it apart. The only things I can think of is the fan hit the shroud when I first tried to start it and I accidentally bridged the battery terminals when disconnecting them (sending sparks everywhere).

Everything powers up when the key is in. The battery reads 12V on my multimeter, but only 8V on the gauge. Everything seems to be connected. What I am I overlooking?

 

1)Check all your fuses
2)The wiring harness is old make sure you didnt rip or kink something
3)Check to make sure your getting fuel and spark
4)Check sparkplug wires
5)Listen to primary injectors
6)Check CAS (try not to take it out of your know its already aligned

IF you believe it is flooded during any time then do the unflood procedure