Well I started working on the truck again recently and I thought you guys would like to see some pictures of my progress. I ran into a problem when I first started where the first engine was not powerful enough so I went back to the drawing board and came up with a raised chassis that will house a series of belts and pulleys to gear down the engine and drive the rear wheels and a larger engine. I finally got the drawings mostly done and decided to make a full scale version out of MDF to check and see if everything would have enough room to work properly. I think I should be mostly ok but I do need to work on the front since I put a cut out for some steering stuff but it looks like I need to remove that and put the angled axle in a lower spot to allow some more room inside for the engine to work without hitting the underside of the trucks hood. Also need to design the pulleys and axles and also figure out where to put the support pieces that hold the two sides of the frame together and to the truck.
Here are some pics of my test fit. Was also checking to see if the higher truck would cause any problems with tipping over but it seems my idea to go with larger wheels worked pretty good at making it stay upright on the ground