2nd-gen trucks are '87 on, so yours is a Gen 2.

US-market '85-on 2.0L engines should have hydraulic lifters, so only the jet valves would need manual adjustment: 0.010" clearance on a hot engine.

That said, jet valves are nonfunctional with a Weber swap, so you may as well just remove the jet valve adjuster screws entirely -- or even replace the jet valves with a "jet valve eliminator" kit, as damaged/stuck jet valves could also explain the poor-running problems you've described.