I have the Australian-made triple-pass unit West Coast Vipers sells (or used to sell??? - I forget the brand name). I did it at the same time as an overdriven water pump (I also have an underdrive crank pulley) so not sure of its effect alone, but mine works well. I got stuck in dowtown Phoenix on a 110F day last year and had to drive home in stop-and-go rush hour traffic (you want hot weather testing - let me tell you this was hot weather testing). Car never made it above 225F. Before the cooling mods it would get very close to maxing the guage out. Runs hotter than the 180 thermostat in cool weather mainly because the fan does not kick on until 207F I believe but once the fan runs it pulls the temp right down.
