New engine, NO crank NO start....

[2 SSlow]

I recently put in an LS2 in my Cumaro, 0 miles on it...Finally got it all back together, and it won't start. Has power, about 12 volts in the battery (a litle low). All the dash lights work, all accessories work, etc. I go to turn the key and nothing...one click is all I get.
When I jump the solenoid on the starter, it will turn over. Took the starter off and had it tested, everything passed.
No security light on, so I know that's not it.
I'm going to bypass the clutch switch just to rule that out, but I don't know why it would have quit all of a sudden...
When I jumped the solenoid, the (-) battery terminal got HOT...like it melted the battery terminal rubber cover lol. So maybe I have excessive resistance in a ground somewhere?
I've check all the fuses that have to do with anything ignition/starting related, but I'm going to double check all of them with my fluke meter when I work on it next...

I'm going to do some more diag when I get home, but I was just looking for some other ideas.....anyone?

I'm really fed up with messing with cars for a while. I hope this pile doesn't give me too many problems once it's up and running.

[LS6427]

Fuel, air, spark.

Air is just about NEVER the issue, unless your TB isn't opening and its sealed up.

Do you have fuel pressure at the rail? Check that fuse too, under the hood. Do you hear your fuel pump priming when you turn the key on?

Do you actually have a spark from the plugs? Fuses don't mean you're getting spark at the plug.

[2 SSlow]

No...the engine wasn't even turning over....the starter wasn't even trying....

We got that issue resolved, but now it just won't start. Has fuel and spark. I'm going to try some 7.350 pushrods. I knew the 7.4's were going to be too long anyway.