ok heres the thing,1972 chevelle,, i had an engine fire and i changed the engine and put some wires in that were burnt but the main power to the starter was melted a bit but i taped it off( probably not a good thing). so now i turn the key and it wont do anything, all the dash lites like gen, and hot come on which always happens. and then i wait 2 minuites without trying and it will work, this always happens. and i just found out that if i leave my lights on and try to start it, it will never start. any help please?!

Sounds like you are either getting a voltage drop or a drop in the amount of current that can travel through the wires. The fact that the wires burnt and it only looks like the insulation melted is not in fact what really happened. When the copper was exposed to all that heat you may have shrank the actual size of the strands, and you then can't pull the needed voltage or current through the same wire.