The clicking is the solenoid making and breaking. Most times that is caused by the solenoid not getting enough current. Could be a weak battery, bad battery cable or connection, alternator not keeping the battery charged, or a bad starter.

 

I actually just had a similar problem with my 2000 SS I just bought it and like 3 days later it had trouble starting. I thought it was the starter relay but it turned out to be a bad starter. Is the clicking noise coming from your fuse box? If so this may sound wierd but take a rubber malet at tap your starter motor then turn it over if it starts after that you have a bad starter motor. If not something electrical most likely.

 

yeah sounds like an electrical kind of thing. notfully shure of what it is.

 

that click click click sound is your starter, if you turn it one time and it just makes a load click thats the cylinder in the starter, and needs to be replaced, oh yea and make sure you completely drained all of the 20W50 out before you added the 5w30, cause 20W50 is fully synthetic oil and most 5w30s arent full synthetic and if they mix and your engine starts to get to normal and over normal temp it can make your pistons lock up, we had someone do it at work they didnt drain all the oil out and added 5w 30 oil to it and the **** locked up, we had to take the engine out drain the **** and take apart the engine block and take the pistons and camshaft out the customer wasnt happy, i never new it would happen either so yea just warning you now