the problem is not with cutting holes in the bonnet - its with clearance with the inner wing on the exhaust side - at least this is true for the 360 - it may be different for the 340 cos it isnt a crossflow engine.
in the meantime take a look at
http://www.higgins340.fsnet.co.uk/
theres some interesting stuff there (even if his front styling is....ahem....questionable! what is that grille....!?
cheers
james