30mm Venturis in Webers in stock '68 911

[68911USA]

I am in the process of installing a K&N Watershield kit to my otherwise stock 1968 911. (I just love the sound, that's all.) I looked down the throats and I can clearly see the markings that indicate that I have 30mm venturis in the Webers, but I thought the stock size was smaller. I don't think anything on the engine of this car had ever been messed with- all the cylinders, senders, etc. all have date codes that correspond with the 10/67 production date, so I can't see why someone would put "bigger" pieces inside the carbs without changing the rest. (It did have a really old sport muffler on it, though- maybe it was meant to complement that.) I'll have to pull the carbs off to confirm the jet sizes etc., but would a 30mm venturi be a normal thing to upgrade to with a performance muffler? The carbs look like they have not been opened up in a long time, still have original banjo fittings and lines on them!

[Grady Clay]

The 30 mm venturi is stock original on your 130 hp 911.
The 911T (110 hp) engine had 27 mm venturi and the 911S (160 hp) engine had 32 mm venturi.

Best,
Grady

[68911USA]

Thanks, Grady! Hope the fires didn't affect you.

[68911USA]

Here's the chart I initially looked at, pulled from the web. Shows 2.0 at 27mm, and the 2.0E at 30mm. This is why I thought it was hot rodded in some fashion- wrong info, obviously! Thanks again, Grady.

Engine Size & Cam Main Venturi Main Air Idle Emulsion Tubes Notes

2.0L 27 110 185 50 F2 Porsche Factory
2.0E 30 125 180 55 F26
2.0S 32 130 180 55 F3
2.2E 30 125 180 55 F26
2.2T 30 125 180 55 F26
2.2S 32 130 180 55 F3
2.4T 30 130 180 60 F26
2.4E 32 135 180 55 F26
2.4S 32 135 180 60 F3
2.4 CIS T 30 130 180 55 F26,F3
2.7 CIS 32 135 180 55 F26
2.7 CIS w/Tall AV's 34 140 180 60 F3
2.7 E, S 34 145 180 60 F3
2.7 E, S w/ Tall AV's 36 155 175 60 F3