transmission cooler and rear transmission seal

I would definetly run a tranny cooler, it can never be too cool, especially with a high stall converter. Your trans fluid will last longer, better shifts, overall, better for your trans. I think most brands will work fine, B&M makes good ones. You can find good ones at your local auto parts store. I got a truck/rv one for my 74 Satellite, it is a bigger one. Be sure to check how they mount, some have brackets and hardware, some have plain old plastic straps that attach to your radiator.