I was wondering what the tightest center you could run stainless marine gen 111 exhaust. i have one set of manifolds already and all the material to build my tailpipes but i think it may be to tight to use them.
any help would be appreciated.

Think Gil’s need 34 min for a reference. Cmi etops 33. Not certain on sm gen 3’s

that is what i was afraid of. i believe the gen 111s are a bit wider than gills. i think i am at 34 1/4

My old boat was extremely narrow c to c. Etops would touch at 32 3/4. 12 meter is only 33 1/2 and the big tube stellings clear with about 1 1/4 btwn center pipes. That will tighten up some with the aftermarket heads with raised exhaust.

Depends what deck height and heads. On a 9.8 deck with standard exhaust ports I believe the fit at 34, raised port heads 34.5, tall deck 35

You can angle mill the exhaust flange on the Gen 3 manifolds so they hug the block better. My tall decks are tighter than 34 inches and the milled Gen 3 manifolds fit.

bingo. That’s what jerry did for me when I put gen 3 ‘s on my OL. Mine were at 34 tall deck , Merlin heads .

thanks a bunch guys. i double checked today and i am right at 34 1/4 i have one pair of gen 3 already, maybe i will mill them just to be safe. i have to build my own tailpipes anyway.
U happen to remember how much was milled or at what angle?