Get a shop to give it a good once over
Questions: Is metal float OK? Is 2-pc venturi OK? (Reading about "stumbling" or "hesitation" related to 1-pc venturi). Other suggestions on rich running?
Give Precision Airmotive a call in Everett Wa. for the full scoop. They also have info on their web site you should check out, with trouble shooting symptoms and basic but fairly detailed overviews of their carbs.
http://www.precisionairmotive.com/ (Click support)
Their trouble shooting manual list a bunch of items and remedies for rich running, caused by: bad primer, wrong venturi installed or incorrectly, float, Bad accelerator pump valve, Accelerator pump stem packing, Sticky float, Float valve not seating, Worn out needs overhaul.
Hesitation: Idle mixture adjusted to rich, Idle tube air-bleed blocked (torque 3-5 in/lb), Pump plunger linkage mis-adjusted (too much fuel on acceleration).
Floats over the years keep changing: metal to plastic, than back to metal and now a new improved composite. The last metal and new composite floats are still in play, at least the last iterations of them. If your metal float is not leaking, corroded and the needle seat and hinge is not worn, good to go. Its your money. Why fix if it ain't broke. A new float kit is not too bad money wise. I think about $135.
Two piece venturi? It's fine, if its not separating, loose as I have been told. The one piece had some problems due to poor field installations, as I understand it. Some think the two piece has better flow? See Precision's site for service bulletin MSA-2, rev 3, 10/95.
Despite all the groovy info, you might want a qualified shop with equip to test it and give it a good eye ball inspection (not even a rebuild just a once over).
As far as the alternatives to carbs, Ellison is fine but expensive and some have a hard time setting them up. It relies on a spray bar with tiny holes so fuel filtration is key. The other, AeroCarb looks like a toy. You really can't do better than the stock Carb. They are dirt simple and reliable. Unless you are going to do sustained inverted flight, the crab will serve you well. The alternative to a carb is drop $3,500 plus on a fuel injection conversion.