That power plant came with an early version of the 4L80 trans. I had a coulee of k5 blazers during the 99's. One had 360k on the same 6.2L engine. Injector pumps go about 100k, we're about 500 bux rebuilt right. The 6.5L had a turbo. Injection pumps had issues with the electronic controller overheating. An aftermarket solution moved the controller to the firewall, lasted longer. If you overheated em a back cylinder may develop a crack. Taken care of its a 300 motor. Most werent. Regardless of engine you are buying a run out van engine and trans, rear end for 9k!4k, 5k? Maybe take a chance