So I'll probably take the dive on a 33 kit in the next few months after finally getting the go ahead from the significant other. I'd like to make sure that we can both enjoy this car and will need to keep it an automatic. The only other concern is heat since we live in Phoenix, AZ. So that brings me to my question.

What is the coldest running engine/trans combo people are running with? I really would prefer to drive it almost daily and need it to be able to cope with stop and go traffic and 120*F ambient temps without breaking a sweat (see what I did there?).

Physics tells me a smaller displacement motor generates smaller explosions and therefore less heat but then you have to throw compression and differences in cooling characteristics from more efficient coolant paths in the block etc...

Who can point me in the right direction?