So... just how big of a supercharger/nitros shot are you running to get 400 HP?????.

I'm assuming your talking about the 289 you list in your profile. I'm not trying to burst your bubble, but unless your running MAJOR modifications and $, your HP figures are likely about 100+ too high.

If you are serious about the HP, the 8" will be the least of your worries. In reality, the part that will break will be the weakest parts. So in order it will likely be the clutch, U joints and tranny before you break the 8".

Even behind a moderatly modified 289 which is what I assume you really have, the 8" should do just fine.

You can always do as Bob says...........................

"I've often heard, or read, where people claim to have a 9" when they actually have an 8". Either they don't know any better, or they're doing the same thing they do about their hp rating."