There is simply no better forum for the GT40 then http://www.gt40s.com
Known the world over, Most any one who is involved with any aspect of the GT40 is a member of this Forum.
There is simply no point in trying to re-invent the wheel and place a competing forum online so we suggest you visit and indeed join the GT40s.com forum if you are at all interested in the GT40 in any way.
Here are a few interesting threads from the GT40s.com forum
This thread is about original GT40 cars at the Classic Le Mans race, Many great GT40 photos in this thread.