I have been running gutted stock mufflers and because of the salt water they get pretty nasty looking not to mention the rust in the driveway. A while ago I picked up a B&S Stainless one and finally looked at it for gutting. I must of bought this after too many brandies as the outlet is straight down if I put it on my 36 PD. Also it may or may not have baffles as the outlet tube runs full width in the center and is perforated. This must have been made for the 35 B&S horizontal engine. Any suggestions folks? Oh, yes I TIG weld.

Weld an elbow on the outlet to face backwards, pretty easy fix

Don't the new prodrive exhaust point down now? I know I bought a replacement exhaust and it faces straight down, I run it with no issues.

I don't think the downward direction of the outlet will change your rpms much. Before my engine work I turned around 3750-3800 depending on the load with a stock gen2.

The outlets the point straight down are for horizontal engines.
The exhaust for vertical engines on the prodrive have an angled outlet.
It will not affect performance, and water wont get up in there.
Worst case scenario is, you might end up with a little black soot on your cav plate.
I ran a horizontal exhaust on my prodrive for a long time.