I have a buddy with a 89 242 formula with the silent thunder exhaust that runs through the swim platform. He just built a new engine(warmed over 454, merlin heads, Madara cam) and needs some performance manifolds or headers to fit. He tried a set of standard bravo lightnings, but had to run the tails uphill slightly and didn't work out so well. What are people using on this boat to fit the silent thunder? He thinks it needs about a 3" taller riser, but that is just a guess i think.

Thanks in advance.

What exhaust was on it before??? Did it have a spacer between the riser and manifold????

I haven't seen it, but I will find out.

I have a set of stainless steel risers from a 496 MAG I replaced. I needed to go 2"higher because I went from 5.7alpha to 8.1MAG Bravo I. My engine is fresh water cooled but these risers were $1300 new. can check formula parts online to find best fit.

I had a 242 and ran both standard Stainless Marines and Eickerts. No issures at all with either of them.