Mechanic Job in Salem, Virginia

I blew my mother in my 03 Durango 4.7 I went to junk yard took another 4.7 out a truck it was a 03 too I put it in my darango all sincers are new crank shaft sin. Cam sin. Oil swich sin. Peatal position sin all new every thing works on truck adcept fire to plugs it want fire need help please might have to reprogram computer please help I know it's simple I just can't figure it out