Who builds hot watercoolds?

We all know who's who in the aircooled game but passat/golf motors are a total different ball game. O.K. this is what I want to do - build a motor for my passat that makes 100 hp per litre in other words 150 hp. The standard TS 1.5 made 100hp (impressive for 1975) so I'm after a 50% increase...BUT.....NO turbo,injection,nitrous etc. Just old fasioned lumpy cam,twin sidedrafts,big valve head,exhaust and racing fuel only 11to1 compression. Can anyone build it? PS I dont want to hear about any engine changing ideas , call me stubborn !

muller and muller i think

its a 1500 and produces 100hp, my 1800 is only 110hp and its a GTI engine.
you could try any engine builder, but you will need extensive head work, cam, carbs and the like.
good luck