If you wish to go with a carburetor on a Duke engine you would have to go back to the manifolds used on those engines made in the late 1970's and early 1980's. There were four generations of Duke engines made before the Tech IV. Because of this, those manifolds and distributors probably won't fit the Tech IV Fiero Dukes. Beyond that, you will need a good fuel pressure regulator with a return or a new fuel pump.
" THE BLACK PARALYZER" -87GT 3800SC Series III engine, custom ZZP /Frozen Boost Intercooler setup, 3.4" Pulley, Northstar TB, LS1 MAF, 3" Spintech/Hedman Exhaust, P-log Manifold, Autolite 104's, MSD wires, Custom CAI, 4T65eHD w. custom axles, Champion Radiator, S10 Brake Booster, HP Tuners VCM Suite.
87GT - ALL OUT 3.4L Turbocharged engine, Garrett Hybrid Turbo, MSD ign., modified TH125H
" ON THE LOOSE WITHOUT THE JUICE "