OK, if you swap in the cam and lifters, get the valve springs right, you know the engine will run fine - no worries there. The upper limit will likely be your intake cfm - carb sizing and the log will restrict it at the top of its range. But you'll still get more "urge" out the motor by a long way over the stock setup.
But if you go to pull up at a light and it's bucking and surging until you drop it into neutral, then the stall speed of the converter is too low. You can either shift into neutral (like a manual) to stop, or source a high stall converter (import killer knows where from).
The trans cooler just preserves your 'box from excessive heat and as the hotter cam can make the engine itself run hotter, the cooling of the trans becomes more separate and of concern. You can go all the way from passive stack plate designs like the Earls, through to fan-assisted units. I say the bigger you can afford and fit, the better.
I am yet to hear of an auto running too cold, but it may be a possibility in extreme winters. You would just "mask" the cooler like a radiator.
Adam.
