T/C or V/B, which first?
 

Which fails first with horsepower upgrades, and which one (aftermarket) is needed most

Hello,

VB first but shortly after the TC would be smart. The VB increases line pressures, provides proper lub in Park, decreases shift slippage and several other things that are a +.

Damon

It's kinda like the chicken or the egg... If you go a lot of power and you are blowing through the converter or making it slip, it will cook the oil. Also if you have lots of power with a good converter, you won't have enough line pressure in the trans and then you will start to cook the clutches.

If doing one, you better do the other.