I have an early 2wd head, in fact one of the very first batch fitted to early 3dr's with the 21.5mm washer on the bolts instead of the standard 23mm
I've had quite a bit done to the head on mine both porting but i also had to mill the bracket on the side to allow for a large compressor housing on the turbo then the centre 6 bolt holes had to be opened right up to allow long studding