If the quadjet carb is not an actual motorhome version, it will work somewhat, but you will need the correct carb. They are actually different
internally. Dick Patterson is your man.
2012 Phoenix Cruiser model 2552
Sirum GMC of Okeechobee FL has original GMC Motorhome carbs that have been rebuilt by a competent rebuilder. The rebuilder actually runs them on his
own GMC and tweeks them before turning them over to Jeff for sale. You may want to check with Jeff at Sirum's. They are priced reasonably. JFWIW
78 Royale w/500 Caddy