You can purchace the metal from AMD, goodmark , search auto swapmeets at your local exposition center, check craigslist daily for your area for 1970 challenger, word of mouth guys here sell stuff all of the time. I would start first buy stripping all parts, bagging and tagging the car parts like I mentioned make reassembly esier and time management better. Looks like you got space for a rotisserie they can be purchased or made. when you are down to the body strip it with aircraft stripper to the metal and then clean several times with solvent after water neutralizing then do the neccesarry body work. You may want to collect all of the needed parts first or work as you go. I am not doing rotisserie but helped my father in law with his cuda a little bit. He made his own rotisserie . Do the same with the 440 dissassemble , bag tag, stripper to the metal then nuetralize water nuetralizes , pressure wash the block and then dry with compressed air . Paint with high temp hemi orange or chrysler orange paint as the block will fash rust quick!! I would do the machine shop work before soon after dissassembly have block tanked and tested, crank and cylinder bores bored and honed if neccessary ( if it has Taper or lip at the top of the cyclinder bore if over 7 thousandths wear ithink bore up ) I may be wrong but i read somewhere that a standard 375 block recommend only boreing to 20over. HP block had more nickel in the block and can go up to 60 over. Not sure if this is horsehunch have heard they are all the same casting just differ internals. Phew!!! did i get it all.
Sorry had a few drinks may need a translator.
