Auto transmission slipping when hot 1997 VS series 2

[Immortality]

That's not true at all. More fluid means more time for it to heat up, also, once you are moving at a reasonable speed the air under the car isn't really that hot, no-where near as hot as the fluid in the pan so there will be some cooling effect but that isn't purpose of the pan. If you want a pan that has more ability to cool the fluid you would need an aftermarket pan with external cooling fins.

All automatic Commodores come with transmission coolers, if you wanted an extra (external) transmission cooler then that is a different story.