Hi Im thinking of upgrading my stock 454 magnum manifolds and risers to high performance manifolds and risers. Any suggestions on an upgrade, I don't know much of a difference between the companies producing them, other than they are very expensive! Eddie marine, or Harden, or other companies. If anyone can suggest a nice setup that will bolt right in that would be great. Boat is bone stock 1988 Formula 292 sr-1
Thakyou

Stainless Marine. They’ll support any upgrades that you might decide to make in the future, and they’ll last a long long time.

Hardin also has copies of the Merc/Gil exhaust that were options on hi-perf engines. Those could be options, too.

I’d still lean toward Stainless Marine. They may also fit a little better than the Hardin manifolds (a little extra room between the engines).

I’d have to agree with Tom however you’ll see Zero gains unless you plan on cam intake and heads upgrade down the road. If so then perfect place to start!

...BUT be careful with aggressive cams (lobe separation angle, etc...). Dry pipes offer more options in performance tuning.

Ya sounds good, as I need that little extra room to get my arm inside between the engines when acessing the petcocks and hose removal for winterizing.