I to have a gearvendor. Any way if you go to Gearvendors website you will see they are running them on dragsters with more power then we will ever be able to see. There weak point is not when you stand on it, but rather when you slow down using the motor and transmission and not the brakes. If you tow you will want to remember to turn it off when slowing down with out brakes.
Quote from there website: The product is ideally suited in stock form for cars with 1200hp or less and in this case is virtually indestructible, literally running for seasons of use without maintenance other than fluid. Cars with more than 1200+ horsepower can be accommodated but you should call the factory so hydraulic issues dealing with clutch ramp timing can be properly adjusted for your application weight and hp.