Had the same problem with high oil temps with a NACA scoop on the left side with a 320 cowl on my 235.  I added a lip and it helped some what (very ugly) but not enough, so I went back to the aft baffle which did increase the aft cylinder temp about 15 degrees but lowered the oil temp about 20 degrees. I know one fellow who moved his scoop to the center underside of the cowl and had excellent results.
Rusty