The stock thru-hull tips that are in there dumping into the box are raw stainless and short, about 2-3 inches exposed. The back of the silent thunder "bucket" has rubber donuts that fit around these.

On Nort's 312, as many do, for appearances sake, the stock tips are replaced by a longer polished thru-hull tip, or in my case transom mount Corsa mufflers.

Some aftermarket tips have internal flappers, some don't. Run external rubber flappers regardless to assure no water ingestion.

stock tips... short raw S/S with wieghted internal flapper

silent thunder "pan". you can see how the exhaust is routed together per side and split to exhaust outlets. Also note the rubber seals I spoke of, and the two L-brackets that support the middle of the box in conjunction with the bolt that thread into gunnel T-nuts at each back corner.
Put an O-ring and some 4200 on those center bolts and put 'em back in the transom after you take the pan off..

Hope that helps Rob.

No pics, but you've already seen them...I took my box off and just installed the rubber flappers to the stock tips. They are short and "hidden" under the platform so I couldn't see spending the money replacing something you can't see when in the water anyway. (and the rubber flapper will nearly cover the entire stock short tip also)

Hey Rip,
Helping a guy with a 271 replace the seals on his box. Obviously, we need new "doughnut" seals but, is there also a seal where the box mates to the platform?

In your pics it looks like there was a seal or some adhesive on top, aft section of the box where it bolts-up to the platform.

Any seals/adhesive on the sides?

Thanks,
Bird

Added polished pipe tips, and rubber flappers. Mufflers? No way!


Don't have them now either.......

No, and No

just the donuts.

Personally, I'm a fan of angle-cut tips....

Me too! Sweet pic Chuck!