Does anyone know if someone makes a exhaust brake for the 6.5 turbo h1?

 

I doubt it - the valves in these motors aren't really strong enough to take all of the extra backpressure that makes the brake work. I'm sure you could but a pac-brake on it, they are pretty easy to install, you just need a section of exhaust thats 3" diameter to stick it in. Don't know how long your top end would hold up though...