Boats a '92 TG flat bottom notched transom and getting rigged with IV SSM's on boxes 1.5 ratio. Locally, I have a friend rebuilding everything and getting some info on shaft height. He's thinking at least 1-1.5" above the planing surface but thats an educated guess as of now. So I guess what I'm looking for is a second opinion so when we get together I already have an idea of were i should be. Also if anyone has experience with this set up, what a good starting point for props would be. I'm only running 500's but down the road will be blown (750-800hp range) so a used set of four blades will have to suffice til then. Thanks

ask Biggus.... He will know, he always knows!

That's a heavy boat, mild thunder will chime in I'm sure, he runs his 4's on a 38 fountain 1.5" below. I'd say with the boxes about even with the running surface. I have a jig for drilling and cutting the transom for Ssm's if you want to rent/ borrow it.

That would be great. Thanks!

I have a 38 topgun with #5 drives the gimbles are 6" from the notch

Send me an email we'll figure something out
[email protected]

Will do when i get a little closer. Thanks again

Boxes or not?

not i have #5 with 950hp with plug in trans

I think it will be difficult to get on plane with 4 blade props. My brother did a flat deck (no notch) with 4s and boxes and put the drive shaft about a 1/2 inch above the bottom. The boat does a big burnout with 5 blade, 17.5 diameter props. For an all around boat I would go around 1.5 below the bottom. At the speeds your going to see with 800s I don't think it will hurt you any.

But you can always space down, going up is tough.