I was told by James at msd that Weber iw 158's which are 380cc were the biggest I could go on ofab. They come on fiat coupe 16v turbos as standard. There are other Weber iw injectors that come on lancia delta integrale's standard which are a similar size give or take a few Cc. They are both beige in colour.
I will be running 158's on my zetec turbo build, hoping to achieve around 280hp.

Grant