[Gaz64]

Dean,

I would think the booster nozzle height would be the same between the S (Spanish) and I (Italian) carbs.

With the whole e-tube assembly sitting lower, the first row of holes becomes exposed at different airflows between S and I.

If you lower the float level to make the first row of holes all even in respect to the fuel level, then the S carbs have to lift the emulsion higher to get to the nozzle.

Some would call it being picky, as you may be chasing something you'll never be able to tune out with "normal" practices.

I personally feel you should have 4 carbs from the same country, be it Italian for authenticity or Spanish for cost.