85 vs 86 same/different?

[GM72K10]

Just picked up an 86 parts truck from an impound yard with a near perfect bed for my 85 K20. Turns out the 86 truck runs (got it with no keys or title) pretty good too, 350, 4 speed, 2 wheel drive, ps,pb. Has a very good factory dual exhaust. Also turns out the truck is a C30 not a C20 as they thought. First off, in this era truck, are exhaust manifolds the same for 2wd vs 4wd? Second, is 86 the last year for a carbed engine? All sheetmetal, grills, etc. look the same. Any drivetrain differences, other than the fact that one is 2wd and one is 4wd? both trucks are 350s. The real shame is this 86 cab is in way better shape than the 85. Too bad the serial #s are on the cowl under the w/s in stead of the post pillar like the 72 and earlier.
Thanks guys.