The 30mm and 32mm are manufactured by EMPI to fit the 40K carbs, and are a little different design than the original Solex ones.  They do not have the "shark fin" in the middle, nor do they have the vacuum hole in the side  They will still work just fine in most instances.  They are a little looser in the body of the carb, too as they are a hair smaller than the factory ones.

Here are some recommendations:

1300cc's to 1641cc's: Use 28mm venturis

1679cc's to 1955c's: Use 30-32mm venturis

2 Liter and up: Use 32mm-35.5mm venturis

For higher RPM engines, 44mm throttle bodies coupled with 34mm machined venturis work exceptionally well.  We can machine them out even larger for racing applications. 

The larger ventris will only breathe as well as your intake manifolds, cylinder heads, and exhaust system lets them.  

Email us or call for help or a recommendation for your system: [email protected]

Note:  You WILL need to change your jets when using larger venturis. We can also supply jets to match every combo.