trans mods???
I'd vote shift kit before upping line pressure. A cooler and pan with gauge would be a very good idea. Keep the fluid cool, <200* is preferable. Don't floor it while cruising and force a downshift from 4th to 2nd if you can help it. Don't go WOT in fourth gear (OD). Avoid exessive WOT shifts from 2-3. The biggest things on that list are 4-2 downshifts and WOT in OD.

