I am in the same boat. I just gutted my hull. 2 sheets of marine plywood $150, 5 gallons of vinylesther resin + 10 yards of 1708 + 10t yards of csm was $340. So for $500 you can be back to brand new. Just do it, seal every hole with 5200, and never question your transom again.

I rigged my 77 scarab 300 for Kaama drives, and ended cutting all of the bulkheads out of the boat due to rot, front stringers were ok. I made 10" solid fiberglass discs where the drives go and used Nidacore for the rest of the transom and engine stringers. I had to move the front engine compartment bulkhead forward 8", and shorten the fuel tank because the trannys are longer.

502, message me I'll tell you how I did mine, and the things you will want to look for. We have the same hull.

I did mine last year, Lots of Fun!!! I replaced the transom core, stringers in the engine compartment, the firewall and stringers all the way up to the helm alongside the gas tank compartment. The bad stuff stopped at the firewall, but I wanted to take that bump out in the lower firewall so I just kept going. I had the gas tank shortened by a foot. Worked out great.
The key is to grind every last bit of gelcoat from the entire engine compartment so as to get a good bond with the new material. I opted to go with epoxy, was worth the extra expense. My goal was to totally re-rig the engine compartment and raise the x demension 2". Nailed it!!

I did all of the grunt work myself and then worked along side a professional to put it all back together.

The bottom line is if you are planning on keeping the boat for a while, if the transom is wet, do and get it over with! Jump in and don't look back!!

Yup I am in both feet and both hands!

Will do man, thanks! Right now the boat is in hibernation but come spring all hell will break loose!

I replaced the transom in my raceboat with Nidacore instead of wood and solid glass where anything is through bolted (drive, k planes). It has worked great for 2 race seasons and I beat the $h!t out of it. 750hp going through a #4 drive on an extension box, no stress cracks at all. I did the Scarab the same way.

If I were you , I would find a heated garage/barn and start now. It's a lot of work and if you are planning on boating this coming summer I would get started!

Yeah I have already faced the fact that I won't be boating with the scarab this summer! I want to make sure this is done right and re rigging for kaamas will be a ton of work also. I will take my time and make sure it's ready for 2016!

I will tear up the lakes with my Tahiti jet!