A cross flow intercooler usually will flow better than one of these: http://www.ebay.com/itm/31-25-X13-X3-25-...=item3cc0e76d61
There is a 180 degree turn in this type of intercooler, bad for flow, & will give you pressure drop, more so on one of these type intercoolers.

Routing tubing, it's easier to plumb smaller diameter tubing.
Depending on your goals & how much power you plan on getting decides to intercooler size you would need.
After you pick the size intercooler you want, get the same size tubing.

I will run a cross flow intercooler, it's not hard to plumb & I ran 45 degree mandrel bent bends as not to hurt airflow/pressure drop as 90 degree bends will do.





MBHD

12 port SDS EFI