So Im cruising down the road in my nova with a 350 that was installed about a month ago with about 100,000 on it thats been warmed over with exhaust, cam and intake. It has been working great since install, but I look down and I see temperature pushing 240-250* (and before I noticed this I had it spinning near 6000. "oh ****"

I race into a parking lot and shut her off, open the hood - over flow tank is full and boiling and squirting and spitting. I let her cool off and start her back up at about 220* It made a real bad grinding/knocking/and real bad squeaking sounds from what sounded like the back of the engine, oil pump/rear main bearing area and oil pressure was almost 0 at idle and like 20 at 2000. I race to a self car wash and spray the radiator with cold water for 5 minutes...temp went down to 180 (squeaking/knock noise still their) and oil pressure is back up alittle-I went straight home....cools down and i check oil its missing 2 quarts?!?!

I checked just over 2 weeks ago and it was fine and it does not burn oil at all. So she cools off and I add 2 quarts. Start it, knock is their...oil pressure is back up but it is still lower than it was.
I pull the valve covers and everything looks fine, oil is right color, nothing bent, everything tight. I readjust the preload, and start her up. noise seems to be almost gone, but still you can almost hear it. I go around the block and open it up but i don't go past 3500rpm, on the rev back down tick tick squeak pop bang knock knock knock...with a sick squeaking noise...I pull into drive way and it doesn't sound too good, almost like a rod is flopping around in their.shut her off and here I am. Also it seemed that the starter was fighting to turn over...almost like no battery juice. It ran hotter and with less oil pressure than usual.
What did I do? What do I do? Spun bearing? Oil pump burned up? Best thing I can think is it overheated first and thinned the oil and vaporized it lol. OR somehow it eat 2 quarts of oil in 2 weeks, made more friction, grinded somthin up, and made it over heat.
Can I remove the pan on a 72 nova with the engine still in? (not sure how much that would help) but I might be able to see whats up.
Depending on the replies I get Im going to pull the engine out tomorrow and take the pan and crank out. (hopefully it is spun bearing or something where i can just remove the crank have a regrind and new bearings and pop her back in?) and possibly its as simple as a fried oil pump?