I have no idea what you're asking becasue the parts I assume you want are so easy to find. I assume you want the 4 wire ignition box that mounts on the firewall and a ballast resister. Quick look at rockauto shows they have multiple brands in stock.

If you mean the computer behind the battery or the fancy lean burn computer mounted on the air cleaner, thats a whole different story BUT one easily fixed by using the igntion conversion kit that includes the ballast resister and ignition box plus a wiring pigtail.

EDIT- 88 5.9 was the last year for any of this junk in the trucks, diplomats etc used it til 89