[MJN]

Yes, I'm on that Napco page and the Napco FB group as well. My Napco parts and service manuals make no mention of front springs and they were not included in the parts diagrams.
I have referenced the GM Heritage site- I have a hard copy book of that information. 1957 was the first year Napco packages were factory installed and the RPO is referenced in the 1957 data packet on the heritage site. All 1956 Chevy's left as 2WD's (GMC's began factory install sometime in 1956). However, anyone could order the Napco kit and upfit their own 2WD or swap the kit from their older truck into a newer 2WD.
I'm not really asking if the springs were part of the conversion kit- theres no information in my Napco material that shows they were. I'm only trying to find out if there are other 3/4 ton's 2 or 4WD with 8 leaf front spring packs. I don't mind having 8 leaf packs made to replace what I have unless the truck is not going to sit level and should have had 6 leaf packs instead.