Lean burn questions

The only differences are the intake and carb, distributor, and controller. The Intkae may or may not have EGR and floor jets (big fittings in the plenum area of the intake), the carb is set very lean, may have cannister purge and/or fule tank vapor solenoids, and the distributor has no mechanical advances at all, and 2 seperate pickup coils (the extra 2 wires..1 is "start", one is "run"). The blocks are the same castings, but with better material, and the "thin wall" thing is just a fable. really. If it were me, I'd upgrade the cam while it's out, and replace the nylon timing gears/chain with a decent double roller too. plug the EGR, and I put allen wrench type pipe plugs in the floor jet holes, and they work well.