No such thing as overcooling. That's why engines have a thermostat.
I just bought a 4-core from Autozone online. Installed it on Sunday. They had 2 different online coupons, so I got it pretty cheap with free shipping. It has connections for automatics, but is considered universal. You don't even need to plug the trans line ports.
Fit perfect and no issues at all.
http://www.autozone.com/autozone/par.../N-iqh3mZ9pdak
I think with the coupons I got it for $130 shipped.