Caddy carburettor/ Weber/pierburg

hi, I'm looking for a 2e2 Pierburg carb for my F reg caddy. preferably in good condition. Am using Weber 32/34 DTML, but am experiencing hassle with it. have changed gaskets with service kit, but still some problem with it. Truck  stalls/judders uphill/ on gradients. Any advice? Have renewed pump and filters too.
Thanks