Whatever you do with it, don't screw this car up. It is too rare and looks bloody excellent as it is. Your mods so far have been intelligent and appropriate. Put a blower on if you must, and by all means fit a worked 186, but remember that LC Toranas were build long before Holden discovered that cars should handle and stop properly. If you are going to boost the power, make sure the suspension and brakes are as good as you can get them. Even if the car is comparitively low mileage, the suspension bushes will probably be the originals which means they are 40 years old and well overdue for replacement. Same thing applies to the shocks, steering connecting rubber bush and possibly hydraulics.