This 83 GMC c3500 The stock 350 engine in this truck runs very well. The Gear 4 speed" also works as it should. This project started by purchasing the 8 to 10 lug wheel adapters from KT Performance for the rear. Then the Good Year 445/509R 22.5 SUPER SINGLE tires and aluminum wheels were added as well as the lowering kit for the rear which lowered the rear eight inches.