hmm, my 85 and 86 efi engines don't have the air rail. but my 89/94 engines do and I know the 84 on carb engines have the rails.
so I guess would would need an early efi engine or an early carb engine.
my 85 2wd carb had the rails, but i know guys with the 84 carbs that have smog pumps so they dont have the rails
