I am building a 454 for my velocity 220. Horsepower will be around 475-500. I need to get some exhaust and am looking for some opinions on what anyone thinks would work good for this application. It is standard bravo, straight out the back.

I would either choose imco powerflows or some imco elbow tops. It really depends on your personal preferance, I think that the cmi polished elbow tops look nicer than the imcos IMHO.

With that kind of hp from a 454, I would assume you are using an aggressive cam. I would suggest you discuss the duration of the cam with the tech support people you buy from (ie -- EMI, Imco, Stainless Marine). You could end up with reversion problems otherwise.

For instance, EMI says their thunders are fine as long as you keep ex. duration under 230. Over that and you need to either go with the stainless risers ($$$) or else add extentions onto the stock risers to make the h2o mix with the exhaust a little further out.