[Burning Pyro]

So heres the story. Last weekend me and buddy finally got my 88 Turbo Supra to racing. we messed around with the wastage a bit to give it a little extra power. it schooled a civic and talon, made me happy. lol. the next night after coming home from the movies we challenged an 06 mustang, suprisgly to me we beat it by about 5 car lengths going from start of highway to end of highway. we let the car sit at my house for a while and we went to start it and it just cranked. everyone said it was my fuel pump, but i was like no, everyone always says that but its not, i check my oil and it was dry, so i had aspar quart in my hatch andi put her in and varooom. so we went to walmart and bought some mobil 1 10w-30.my buddy managed to over fill the thing becuase the next day it died on the highway and i had this happen before. had oil allover the plugs. so i drained the oil, opened up the valve covers so i culd get to that plate that covers the plug valley, i toooked that out and drained the oil. i had my little brother hop in the car and crank it once jsut so i could make sure everything would spin. it was kinda cool, the rags i had in the plug bays shot out lol. but everything spun. and there is compression.so i threw her back together, put in 3 quarts to be safe for now drove for a bit and added the fourth quart. NOW, heres the problem. a few nights ago i heard some knocking, i couldnt tell if its coming from under the car or in the engine. a few friends said it ROD KNOCK. i dont know enough to say what it is. im thinking maybe i could have left a bolt under the valve cover, not saying i did but maybe something slipped in and i didnt see it.theres the story and the symptoms. well also, i dont have a working tach yet,so im not sure what the rpm range it hits at, but it happens when im at a lower range and it goes away, but you can here it when the car starts, but then it stops, had me thining it was belt squeek at first. Please help as i do not want to do any further damage. im going to take the valve covers off 2mr and check it out. thanks for any advise and sorry for the long post.