vb will be fine, it is said that it can hold perfectly for 350, but for me my sprag broke but i don't know how much i was pushing, but i was at 9 psi so.. mid to low 300's? but for you 280, vb is perfectly just fine with the tranny cooler

 

i have the valve body on mine, the shifts are definently crisper, well worth it. i dont have the tranny cooler installed yet though, that will be soon

 

just curious, but doesnt the IS already have a transe cooler? isnt the radiator split some for coolent and some for trans?

 

the IS auto does have a stock trans cooler but you need an upgraded one for trans after the vb install, its not very expensive and easy to install.

 

ok so what do you do about the lines going to the radiator? do those lines just connect into a new cooler?