FREE 360 and 727 for son Duster!!

My son recently made a new freind when the gentlemen stopped to look at my boy's 73 duster when he was gasing up. We later found out he managed a junk yard when he called to offer my son a free 1977 360 and 727 trans!! It came out of a RV. He said he was impressed with his politeness and how proud he was of his car. (Me very proud of my boy for that!!) OK, so now we got a project, cool, only I'm a weekend warrior at best and have just enough knowledge to be dangerous! I got a stand and I'm tearing down now and it's down to block, crank, cam and pistons. I'm now am trying to under stand how the motor works as I rotate around an watch what happens. I know the firing order of the sm block mopar but i'm confussed about where TDC is. When the #1 piston is at the top of the block, there are 2 different cam locations (180 deg and 360 deg.) In one possition the cam lobes are between the opening of the exaust and intake lifters. In the other the cam lobes are both rotated down out of sight. I already took out the distridutor out so I dont know witch is TDC. Maybe i'm way off on the hole thing!? This is probably just the start of all my ?'s but I really want to do this with my son. Can't be that hard, or can it??:-k

Thanks for reading. Any help and or advice is greatly appreciated!! (Prayers are good to!!) Benson and Dyllon