Auto Parts: 1981 Ford F150 Carb, fuel delivery system, variable venturi

Question
I have the 302 V8 on my 1981 f150.  It is a veriable venturi carberator.  I usually have trouble passing CA smog every 2 years.  Any suggestions for CA approved replacements (non VV)? should i have it rebuilt (or attempt to do it myself), or buy an already rebuilt one?

Answer
    The variable venturi carburetor is a real problem for mechanics and parts people.  There were many attempts to come up with a conventional replacement, but there was never enough real push behind it.  The principle is a very sound one, Stromberg and SU have been using it in Europe and (by proxy) in Japan for decades.  Almost all motorcycle carburetors work on the same principles.  The Ford VV carb suffered from lack of understanding by mechanics, a lack of real commitment by Ford, and less-than-ideal assembly quality.  Rebuilding the carb is not super difficult, if you have some experience with carburetors and how they work.  If you have never done this before, I would be leery of attempting it.  A rebuild kit for this carb includes new diaphragms and is not real cheap; rebuilt carbs can be had for a little over $300.  The first thing you should do, though, before attacking the carburetor, is a tune-up.  So many people attempt to tune or modify their fuel delivery system without making sure that the ignition system is up to snuff first.  There is some art and experience needed in adjusting the fuel system to work properly, but very little is needed to ensure that the ignition is working properly.  Sometimes just changing to new spark plugs can produce a very large improvement in combustion efficiency.  So, before you even think about working on the carb, replace the cap, rotor, wires, and spark plugs.  Then set the timing and verify that the advance is working correctly.  On vehicles of this vintage there are frequently problems with the ported vacuum switch.  Most people won't replace it unless it breaks off in their hand, but its function should be verified and it should be replaced if that function is not correct.  Put a new PCV valve in and verify that the crankcase breather (that little sponge in the side of the air cleaner) is free of dirt and obstruction.  Then get the emissions done, you'll probably pass.  If not, then find an old Ford man to look at that VV carb.  California residence makes this emissions work tougher, because their standards are more stringent and they are less likely to "cut slack."  This truck ought to be able to pass, though, if it is in good shape.  Of course, if the engine is very worn it won't pass no matter what you do to it.