Mobo's with side exit exhausts

[MYStargazer]

Are you possibly talking of those labeled as "unique style" in their GIF banner below?
Excellent choice anyway, over the pond Corsa exhausts are widely used also in very high performance boats, not just skiboats.

Yes - I just found a PDF brochure for them. Here's an extract from a screenprint.

 

[JOHNPEET]

Perkins installation guidelines were pretty much the industry standard of 3 inches of Hg, you need to have pretty nasty tortuous system to be on that threshold.

The Perkins manual that I have for this engine states max EBP of 13"WG but happy to be corrected!

Agree the current Perkins range is 40"WG.