Thanks guys for all your help.
I picked up a pair of second hand heads from QLD. The original GT40 heads were difficult to source. The heads are due to arrive next Tuesday and hopefully the machine shop will have them ready by Friday so I can put the boat back in the water in the weekend for a test run.
In the mean time I have been detailing the boat. All the interior has been removed so the gell coat can be polished and carpet professionally cleaned.
I'm also tying the get the heater back in the boat. I pressure tested the unit and it is fine it's just the motor will not function. When I plug it in it seems to click when I turn the switch but noting else. Hoping if I clean the terminals up it will come back to life. If not I will have to start troubleshooting and possibly try find a replacement motor. can anybody confirm the connection point of the hoses to the engine. From what I have researched the connection is on the drivers side of the engine below the head and the bottom of the cast U elbow on the front of the engine.
Lewy I thought yours was rear mount?