Hi Stew,
Sorry for the late reply been on holiday, there is no need to remove the standard laminar cooler, all you need to do is swap the 90 degrees end with the straight end - no problem. I have seen people fit a 180 hose from the straight end which closes up so much because it touches the monoque that I doubt that any flow passes through it at all.
It is very important that the cooler is fitted to the KV6 to eradicate the problem of thermal shock to the block and heads, Evans waterless coolant is the business by the way, you can remove the header tank cap when the engine is up to temperature with out it boiling - the system does'nt pressurise because Evans doesn't boil in the water galleries around the combustion chamber like water does - go for it.
Enjoying the car by the way, it's good having a car you can race motorbikes with is'nt it