You want to use 3/4 marine ply for the transom the coosa board stuff needs to have stainless spacers installed with every major bolt or else it will compress i believe. From what i heard it can also flex too much for a high performance application. Plywood is still the best way to do it and is 100 bucks a sheet normally for marine grade vs a lot more for coose i think.

Its funny everybody always has the same questions, epoxy, coosa board, what to bed the plywood in with. Search the fiberglass forum for glass daves posts about everything. I researched for months before doing mine haha.

After a back injury and then a hand injury I'm back at work on the Transom, I got a little over half of the old one out..... and Boy, is it slow going. I'll post some pictures this weekend.

Todd

What ever happened to this project?

I own it now, It's got a Coosa Transom with 2" wide Coosa Stringers with Carbon Fiber and Kevlar Gussets with Epoxy (No More Wood in the Engine Bay) I've got a 415ci Ls and a Bravo. I'm making a Mold from the 90lb Engine Hatch and will make one thats 20lbs or so with Carbon Fiber.. I still need to measure for Headers..

https://cimg1.ibsrv.net/gimg/www.off...8f61f807c3.jpg
https://cimg9.ibsrv.net/gimg/www.off...a854b8a081.jpg

There is two of those Gussets on each outboard side of the stringers, and two more Plys of Coosa as well..

https://cimg5.ibsrv.net/gimg/www.off...cb7c4a61c4.jpg
https://cimg0.ibsrv.net/gimg/www.off...089e8ea4cd.jpg

who's pulley system is that ? looks nice

Hardin Marine, I Believe I've Made their Christmas for the Past Two Years.. Lol

Looks like Hardin Marine for the LS. Has the sea water pump below alt.
He don't have the pulley on it.