Well its pretty much a done deal. I started the transom rebuild about 2 weeks ago and just finished my last pour tonight. Thanks to this very informative post by Mauryc I had the courage to give this a try.
http://www.wellcraftv20.com/communit...ead.php?t=8830
My 78 only used 2 5 gallon pails. I need to mix up about another gallon to fill the sides up but thats about it. The biggest surprise was the amount of arjay I lost through some holes I couln't seal inside the transom. I was able to plug them up from inside the boat to stop it from all running out. Hopefully it all holds together.