Well...yeah. Holley made ONE of those, and raffled it off to some lucky bum.
Welcome to the L31 Vortec engine. Cross-ram, multi-point injectors. OEM reliability. Stock-looking for '96-newer 5.7L. Power band pretty-much exactly where you want it.
The Treasure Yard will be your friend. Grab the entire engine with the accessory drive and accessories. MAYBE the transmission, and get the computer, and the wire harness. Expect some headaches that are solveable. Use a vehicle similar to yours for the donor--same transmission, same gear ratio, etc.
Or sell your truck, buy a '96-newer L31 truck.