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This is my first post, so Hi to everyone.
Regarding TURBOS, they the choice here in Brazil, I guess one of the reasons is because we have alcoohol at the pumps (great for turbos). My daily driver is an Chevrolet (Opel) Astra with a custom turbo system (270hp) running alcohol (my GL is alcohol fed too but it is not turbocharged).
Anyhow, you were asking about the turbo heads. From my experience (I'm also no expert, but I have been hacking since I was 15 and I'm 32) crossover between turbos and normally aspirated engines, when it come to heads, is huge. Here, in the beggining people expected a turbo not to benefit that much from head work/design, but it does. It doesn't benefit from big intake valves as much though.
Summary: D ports will work in a turbo motor great. I would (depending on engine size) go with a 40 or 42 intake valve and the biggest exhaust valve possible. Compression: they don't benefit (horsepower gains) that much from a higher compression under boost (we find 9 to be the number on alcohol engines, so you figure for gas when on normally aspirated engines is 9 for gas and 13 for alcohol on aircooled VWs).
There are people making some interesting kits where the turbo sits next to the transmission (much cooler than the ones on top of the engine) here in Brazil.
Best regards to all.
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