1979 chevrolet 2wd PU, Here's the story.... pulled it into the garage to replace a seized drivers caliper ended up replacing, hard and soft lines, proportioning valve, master cylinder and so on. truck sat for +6 months. Finished up and the battery was dead, whipped a charge on it engine won't turn over. Figured the battery lost a cell and was bad, replaced it same story won't turn over. Figured the Starter was weak replaced it same story engine won't turn over. So now I'm not sure what my next step should be. The motor is free it will turn. I took the plugs out yesterday sprayed some WD-40 in the cylinders re installed the plugs and wires same story won't turn over. Starter turns the motor a bit then starts clicking. The motor ran just fine when I parked it. So there it is I need some opinions on what to look at next. Thanks for your input.