Fuel system - Carburettor Pierburg alternatives
Syncro I've been told the carbs you would benefit from most are twin dual 40 Dellortos. You want to run 34mm Venturis for maximum BHP, or 32mm Venturis for max torque. Likewise 140 main jets for BHP with the 34 Venturis, or 120 - 130 mains with the 32s
You need type 3 manifolds (little tiny ones) and pancake air filters to get it all under the engine cover, and a pair of inlet manifold gaskets to use as a template to Dremel out the manifolds so they fit the DG cylinder head's inlet port. Any standard aftermarket beetle twin carb linkage is the last bit you need - CB performance ones are excelllent.
These bits are available from Jim Calvert at Stateside Tuning, the carbs are best got from Alfa1750 who trades on Ebay from Italy. Just do a search for Dellorto carbs. Tell him what size engine, and he sets them up and balances them for you on a factory original syncrometer - excellent!! DON'T be tempted to put Webers on a T25 - less smooth. DON'T buy Velocity Stacks (trumpets) as they won't fit inside the small air filters!!