hello mike , there were only some minor upgrades at the porsche 914 , injection was removed due not verry reliabel , and a double weber was add in place , this made the car mutch faster and reliabel , an electronic ignition was placed , and the 5 bolt wheel were made possible by a friend of me turning an aluminuim piece with 4 bolt insert and 5 bolt outsert , so first jou mount the 4 bolt alu piece on the brakes and on that alu piece jou could mount the 5 bolt fuchs rims if jou untherstand , it was stil the same car , the fuchs were aftermarket wheels 5 bolt