What parts are needed for a carbureted LM7 5.3 build in an 83 Monte Carlo SS?

Beyond mounts, oil pan, headers and cooling (the same as any LS swap), carbing the LM7 needs:

What carbing an LS takes (Speedway):

• Carb intake: single- or dual-plane, from about $279. For the street, a dual-plane (roughly 1,500–6,000 rpm) gives the best bottom end and mid-range.
• Ignition controller: every LS is distributorless, so you need an LS ignition box to fire the coils. Boxes like MSD's LS unit use the factory crank and cam sensors and come with basic timing curves preloaded; a laptop is optional for fine-tuning.
• Fuel: no mechanical pump option on an LS, but you don't need 58 psi. A low-pressure electric pump that flows 80–130 GPH at about 7 psi needs no regulator or return line. An inline pump must sit below the bottom of the tank.
• AFM engines: replace the cylinder-deactivation lifters with static lifters for any carbureted build.
• Throttle linkage: the stock linkage may work with the right adapter, or use an aftermarket cable.
• Gauges: you'll need sensors that match your gauges.

The LM7 doesn't have AFM, so its factory lifters stay. For a street car, Speedway's carbureted 5.3 recipe used a dual-plane intake, a 650 cfm carb and an MSD LS ignition controller.

We don't have G-body-specific mount and header part numbers verified; use the planner for the chassis side.