Rob & Dave to the rescue again
Top Sticky -
http://www.vw-resource.com/jets.html#30
The standard jetting that the 30PICT/1 & 2 carburetors came with is size X122.5 or X125 main, size 55 idle, and size 125Z air correction jets. The 30PICT/3 and the H30/31 carburetors came with size X112 main (super lean), size 65 idle, and size 125Z air correction jets, which made them very difficult to tune. The larger size 65 idle jet helped the 30PICT/3 and H30/31 carburetors overcome the very lean main jet at idle and low speeds, and thus help to reduce the "bogging" problem.
When using the 30PICT or H30/31 carburetor on a twin port manifold and any vacuum distributor, change the jets to X125 or X127.5 main, 55 idle, and leave the air correction at 125Z. Try the X125 main before you try the X127.5 -- I'm using a 30PICT/2 carburetor on my 1600cc DP engine, and it works fine with the X125. But engines do differ a little, and the sizes above are "ball park" figures rather than definitive.
Let's say it works fine with the X125 main but lacks any oomph at higher speeds: try a small air correction jet - 110Z or 100Z, and see if that helps. (See the discussion of the air correction jet above.)
As for WHERE DO YOU GET IT
Where are you buying a NEW carb fron?? Aircooled.net??
If so get them to rejet it. They sell new jets.