I have, currently, no engine in my K5. It is stripped down to the point where I need to make a choice. Do I want a gas or diesel engine? If I go gas, it'll be a 350 with a 465. If I go 6.2 diesel, it'll be with a 465. If I go 6.5 diesel, it'll be most likely with a 465 or a 4500. (not sure if the 465 will bolt up) If I go 4bt route, it'll be the 4500. If I go 5.9 Cummins, it'll also be the 4500 most definitely. FYI, I am basing my options on current petro price trends, and not having anything in it at all allows me to have whatever budget I need to get it done. Gearing is set at 3.73 with a 35" all terrain. Give your opinions please!