Conclusion.
Thanks to all who helped me with this.
The final problem was a defective fuel injection pump this was causing the engine runaway, I think when I originally tried to remove the timing cover (without fully reading the manual) I bent the pins inside the pump which on start up then gave the engine full fuel all the time.
I got the pump and injectors rebuilt and engine now purrs like a salty kitten.
A $1000 lesson learned. Lol
Thanks to all.