Having done this mod with a mate on his VY series II utlity, we purchased the genuine kit from holden which provided about a fifteen page instruction manual which covered all the necessary steps to install the gauges. It took us approx 4hrs to do on a saturday morning as there is a lot of parts to the dash that must be removed and refitted. The only wire to go through the firewall is the oil pressure sender unit wire, the rest are connected into the wiring harness within the dash. We fitted the gauges to a six cylinder but the instructions do suit a V8. Approx cost of package $660.00 from holden. You had to do some minor electrical connections and joins but otherwise was staight forward to do!! Follow all instructions carefully and you should not have any problems. The package & instructions covers both vehicles with climate and non climate air!! The instructions are also printed with colour photos. Good luck!! :yeah: