The OEM connectors refers to the inlet/outlet on the intercooler. The factory inlets/outlets utilize a male/female connection which necks down to about 2". We offer an alternative to the OEM which consists of a larger 2.75" inlet/outlet on both our 5" & 7" models. These are currently available for pre-order at a discount and are expected to arrive in the next 3 weeks.
The 5" version isn't available in OEM connectors, only the 7" and we have a very limited amount of 7" OEM models in stock.
There's about 2" worth of trimming of the shroud on the 7" whereas the 5" is a bolt on affair without any trimming required.