'90 Y-Pipe Conversion to Straight Pipes

Here it is with a few pics to give everyone an idea how it went and looks. Took me three hours and I mostly took my time. No real complications to speak of. Made my initial cuts on the 3" Hose intentionally long to compensate for bends etc. and cut them back as necessary- Wound up making two cuts to each hose to get them to the appropriate length.
Thanks to Boat Dr for his excellent advice and time on the phone. The only place I varied from his instructions was to keep the original 4" pipe about 6" longer than he recommended. I played with a few things before cutting and think where I placed the Y is working great for my application. I will try to place the pics in sequence.

Sounds phenomenal. Quiet at idle in the water and awesome when on plane. No bad at all inside the boat but I haven't been pulled behind it yet. All in all i'm glad I did it. Met all my expectations and then some.




Y-Pipe placement about 6-8" Further forward than Boat Dr's recommendation.



Checking floor fitment and mocking before cutting





Although it may appear otherwise, The hose is making very minimal contact on the tiller cable. It is pressed against the port stringer which is supporting the hose's placement.




All done and went together very clean. Looks like it came this way.

Nice work, and great post!

Running duals is easy... a 4" hose will in fact sneak by the steering components if you keep it tucked up right against the stringer.

The problem with that is the original hole is not in that same location on the other side, so the new hole will end up 6-8" away from being symmetrical. So youre left with 3 options... have asymmetrical holes (kinda defeats the purpose if they look like crap), fill the original hole and drill 2 new ones as wide as you can, or get creative and mirror the original hole.

No, mine is mounted to the bracket on the strut as well. You would have to relocate that at a minimum, I would think.

Yeah post up a sound clip. I have a small crack in my muffler and instead of replacing I was thinking about removing it. Just worried its gonna be too loud. But I don't live on a small lake to annoy anyone either so it shouldn't be an issue.

Thanks

Where did you purchase it from? Looked but couldn't find it anywhere. I know I saw it somewhere, but cant seem to locate it again.

Thanks

RedSquad7 wrote: The older pre HO boats have 3", the GT40 and HO boats have 3.5" risers.

*Almost* correct.

I believe all 1992+ 351w PCM's got the 3.5" risers whether they were standard or HO. My extended family has had 3 '92-93 SN's with the standard engine and larger risers.

I also have the 3.5 risers and std now HO engine 1992...

I know this post is years old. But I want to do this same conversion to my 90. Do you have contact info for boat dr??

Awesome. Thanks.