What is minimum electrical required to start my car?

I get very frustrated with my lack of knowledge. I didn't want to spill it all out as it is a VERY VERY long story.... I just wanted to know how to start a car when the motor is not in the car(what needs wired up and how), I should have said just that and nothing more, knowing how to do that would also help with testing other motors on a stand to see if they will start or not....

But here it is.... try to make long story short
I bought a 74 dart sport last year(318 car - motor bad) and earlier this year I bought a 360 from a 76 or 78 motorhome and put the entire drive train into the dart, cut driveshaft to fit... the motor ran before it was installed, after hooking it up the key did nothing.. hooked up a gas can to fuel pump to bypass the tank, jumped a wire from the battery to the coil and screw driver across relay and it started.... I drove it around the block a couple time like this.. everything seemed to b fine.....
sold it to my nephew, who "said" (hard to believe as he a big liar)(but easy to believe as he stupid as hell) he could not ever get it started... he had the car for a few months before I got it back.... he is in jail now as like I said he stupid as hell.... it did not have a voltage regulator on it and the alternator was replaced and the under hood wiring jacked all up, the under dash wiring was CUT yes cut not unplugged under the dash, all the wiring was everywhere....
I put an under the dash wiring harness from a 73 dart sport 340 car... seemed to work fine... I got a wiring diagram for under the hood wiring... hooked it all up correctly(at least I thought so)but not sure as voltage regulator was 2 prong not 3 as diagram showed... I turned the key... yeehaa the car turned over from the key... but that the last good news I ever had from this car.. it never would even try to start... I absolutely HATE asking for help... so I read many many post from here to try and find all the right answers as I knew someone had answered my questions once before and I did not want to ask I could find them... I found lots but never got it started... I was able to test the voltage regulator - good, test the coil - good, test the dual resistor - good... but I was not getting fire, it would turn over but not FIRE... I kept trying everything you folks have said here at least 20 times before... I finally decided to touch stuff, I noticed the voltage regulator was kinda hot from cranking the car off and on through out the day or just hot from not wired correctly... either way.. I unhooked the battery and brought it in and put on charge so it be fully charged for the next day(brand new battery)... next day hooked battery up... turned key - nothing...like wtf... it was turning over before and all i did was take battery out and put battery back... now nuthing... it also has the safety belt stupid thing under hood for that year also- dont think it problem but do not know... I just said hockey Puck this and gave up for a while... but need money to help my son so hafta get it going and sell it.... so there it is... trying to eliminate ALL electrical currently on the car and try to start it - just to make sure my idiot nephew didnt ruin it somehow,,,, then once I get it to start I will start hooking stuff up.... just want to start it without cars electrical.... i am very thankful for all you folks help, i just get frustrated with myself