Has anyone here put a carb on an LT1 engine in a 3rd gen firebird? How might it affect horsepower, fuel economy, and can the LT1 intake be used? How tough would it be to switch the distributor?

 

You need a special intake manifold unless you're accustomed to modifying and fabricating your own parts. GMPP makes an intake designed to bolt on top of an LT-1 and has the hole in the back for a standard rear-mounted distributor.

What you do with the old Optispark I have no idea. Probably just leave it bolted on but don't hook it up to anything.

Fuel ecomonmy will probably suffer somewhat, depnding on how sharp a carb tuner you are. Torque is probably a little better than the LT-1 intake due to the longer dual-plane intake runners, but HP is probably about the same.