[ChrisB]

C16SE is the better engine,better design head as there is no extra casting in the exhaust ports for the EGR,i think the inlet ports are also slightly different aswell,not sure though.

C16XE. It does have the castings in the exhaust ports of the head for EGR, but they don't make it to the outside world.

I wouldn't worry too much about it. When at RRE doing Miles':

Rob: Is that the big port head?
Me: Yeah.
Rob: Thats a shame...
lmao

Inlet ports are huge, certainly don't need making any bigger with head work. Exhaust needs a fair bit of work though.