Reguardless of the engines power state, a oil coller extends the life of oil by keeping it cool as well as helps the engine live longer.
The adapter for the cooler IIRC, should bolt right onto the right angle housing. Clearance issues, with headers should not be a problem since you can run the cooler lines where you need them.
You should also be able to get a padded strap to run the lines though and route them away from the hot tubes. These padded tube holders have a tab to run a screw through so you can mount them on a frame rail to help with the routing.