Good morning everyone,

I'm a new owner of a Formula 1991 357-SR1.
Right now I'm in the process of removing the silent thunder, changing the raisers and manifolds. I need some help!!!

1) Should I use tips for the raisers or just do the raiser all the way straight out? If I'm better using tips, where and which could I find them?

2) Where can I find an aluminium swim-platform that will look great on the boat and not cost a lot of money?

Any suggestion will help

Thank you

Pcrocetti - Let me start by saying welcome to OSO as well as welcom to the brotherhood that is Formula owners. Your about to uncover a wealth of knowledge on this site is irreplacable. If you can't find what your looking for here, then I don't know what to tell you.

I tend to search the forum first to see who or what others are using for whatever it is i'm looking for. Lights, parts, products, etc. I know a lot of people have swapped out the ST platform on the vintage SR-1s for the aluminum platfrom. Another good place to look would be the swap shop. People always have used and some brand new parts just lying around. I've found several deals on this website from owners just looking to clean out their garage so they don't have to store and keep dusting these items off. The classifieds would be the next place I would look. My only concern would be finding that one platform that fits the best, but you should be able to find a thread that someone started on here documenting their project and where and who they got their platform from.

As for your question about the tips and risers. Are you planning on replacing with stock manifolds and risers? Generally there will be stainless tips already installed by the factory after you remove the ST platform. They are not going to be polished but you could always do that yourself. You can just throw some rubber flappers on and call it day or if you want to dress up the stern a bit you can find some nice polished chrome tips and install them. You will of course have to remove the factory tips first. The riser doesn't go completely through the transom. There is usually a 8-10" piece of exhaust hose that clamps on to the end of the riser and the end of the exhaust tip. The tip is what goes through the transom not the riser.

Hope this helps some. Best of luck with your project, keep us posted as to your progress as well.

Thank you so much for your help Splitdecision and welcoming me to this site.
I'm exited about learning more everyday.
I'm putting Stainless Marine manifolds and risers, one of the options they were giving me is to make the risers long enough, they will go through the transom. It looks really nice, 5'' risers coming out the back but yesterday talking about it with the mechanic, he mentioned that when you do that is very hard to seal and will always have water coming in the boat. He also recommended the tips. The old tips, I saw them there but I think they are way too short as far as looks. I will look for some nice tips in here.
I will keep you posted, as soon as I get the job done, I will post some pic too.

Thanks again

Keep talking with stainless marine on the dry exhaust. I had them on a 357 Kamma boat a while back and my buddy has dry on a scarab nija. There is a neoprene seal with a nice polished stainless ring, if I remember correctly. I really don't think you would have an issue with water in the bilge. Dry exhaust is really cool if you are not worried about noise. I also just cut the bottoms out of my silent thunder and kept what I thought was a good looking swim platform. You can also remove the rubber flapper from the rectangular exhaust fitting which alleviates that annoying flapping sound. Cutting the bottom out of the silent thunder also does not adversely impact the structure of the swim platform. Maybe just try it and see before you invest in the aluminum platform. The 357 is a great boat and I enjoyed mine. In the course of owning the boat, I also removed the Kamma drives, put imco standoff boxes and bravo drives on it with external hydraulic steering mounted to the boxes. It is a great set-up with the standoff boxes and bravos also. Good luck.

Thank you for the advice 38f.

I will visit Stainless Marine on Monday and see what they have to say about dry exhaust. The noise is not and issue and the dry exhaust is 5" wide compare to the 4" tips, it looks really cool. The ST that I removed, has the bottom cut out and the noise level was great. Now I'm putting two 540 big blocks done by Mesa Balancing, it went from 600HP to 750HP each, I just feel like I have to let them be loud. One of the reasons I removed the ST as well, is because it holds some water in it and compromise a little bit of performance. Next step I think, it will be taking care of the drives before I change them, because the Bravos I wont hold that power for too long. I don't know yet about the props, right now I have Bravo I 24 pitch. Once I put the boat in the water, I'll check. I'm very exited everything it should be done in about three weeks.

Congrats on the 357 and welcome to the forum.
Post up some pics when you can. We love pics here.
Good luck with all the mods. Sounds like you might look into XR drives for that kind of power.

Sorry for not getting back before, running around trying to coordinate everyone to work together. As soon as I get some pic I will be posting.

Thank you all for the support and help