Re: Carburetors 1988 vs 1994
Both sets of carbs should have a 1 5/8 venturi in them. If you remove the bowls and floats and invert the carbs, the venturi size will be cast on the inside. There is a possibility that the throttle butterflies are slightly larger in the .101 and .098 jetted set of carbs but I don't think so--I never measured the bore diameter of these carbs.
There will be no performance difference discernable with either set of carbs. The difference in jet size between the two sets is primarily because of air bleed and venting. The smaller jetted carbs were on a slightly smaller displacement engine and were expected to deliver a slightly less volume of fuel/air at full throttle. Thus they were jetted and air-bled to compensate.
However, putting them on a larger displacement engine (depending upon engine 1 or 2 cubic inches more--only 1-2%) will not affect mixture. Since as more air flows through a venturi it tends to get richer, the mixture will still stay at normal approximately 16 to 1 ratio. No harm will come to the engine from a lean run condition because it will not happen. ---ASSUMING, of course, that the low speed needles have been correctly set.
As to the other carbs, Not being the engineers, I can only postulate several theorys--They may be correct or may not.
Since both top and bottom sets of cylinders are exactly the same (with the exception of the ball bearing on the top of the crankshaft.) they should draw the same amount of air/fuel mixture. However, since fuel is fed to both carbs through the bottom one, it stands to reason that the top carb would have slightly less pressurized fuel delivered. Thus: it may tend to run a little leaner and the larger jet may be an effort to compensate. HOWEVER, Chrysler and Force engines ran very nicely for years using the same jetted carbs for top and bottom sets of cylinders.
The #2 and #4 cylinders normally run very slightly leaner and damage due to a lean run condition USUALLY affects either of these cylinders first. The air balance tube connects top and bottom manifolds on the #1 and #3 side of the reed plate thus #2 may also tend to be the first cylinder starved for fuel. Thus: the top carb would be jetted slightly larger to try to compensate.
