I have a 81 Cutlass that was originally a 3.8l. I have a 5.7l vortec and 4l60e with wire harness from a 98 GMC 1500. What specifically is needed for engine to work in car? How do i wire it all in so gauges and speedo function properly? Pretty much everything a novice such as myself would need to know. Not completely mechanically deficient, just never dealt with wiring before. Any and all help greatly appreciated.