It sounds more like air, or an obstructed/stopped fuel supply system, for whatever reason. A noisy fuel lift pump does not mean it's moving fuel, or...
My '94 K2500 342K miles, usually fires right up. Batteries are due but I've kept them on a maintainer. Fuel filter likely due for replacement. Check...
The bellhousing design allowed GM to utilize the Duramax in the van application with the 4L80-E automatic transmission (250-hp/440 lb-ft). And, then...