Weber 40 ida 3c

[NZVW]

I HAVE LOOKED THROUGH THE "SEARCH'' but cannot find the answer to my question, which is this.
What engines were these carb's installed on ?
Any help much appreciated.

[OCG911T]

Mark,

I believe those were used on the older “normal” 911s, with the IDS version of the same carburetor being used on the 1967 911S of the time. The only difference was enrichment tubes on the IDS version which helped with the added demands of the more powerful engine.

Paul Abbott is often on here and is arguably the leading expert on these old carburetors. Look up Performance Oriented on google and he has a lot of great information on the older 911 carburetors.

At some point the designations changed a bit for the webers that were used on the 911T and the 914-6 models when they switched to MFI for the 911E and 911S models. Some of the engines also had Solex and Zenith carburetors, but I am unclear as to which markets and models received the different manufacturers...

[NZVW]

Thanks for that Oliver

[1QuickS]

Those are original on 911s from Feb 1966 through mid 1967 year model, note the shaft coupling is a wavy spring with clamping bolts. These were discontinued in late 1967 and replaced with a cylindrical shaft coupling for the 1968 model year.

It is difficult to discern the serial number but it looks like 4XX or similar. Three digits implies early 1966 production date, perhaps April of 1966. I do not know the production rate of 911s at that time but if you assume serial number 1 was first installed in Feb 1966 then your carbs would be on the 4XXth car after that.