It's good to have the Triumph engine numbers experts here!
Perhaps one of you has an idea for the following. My friend owns the 1953 +4 DHC which reputedly was used by Chris Lawrence for testing his developments. The engine in the car has still a Lawrencetune inlet manifold with 2 Weber DCOE carburetors and the cylinder head seems to be "special" too, as is the exhaust manifold.
The engine number is simply X 773 E. A Chris Lawrence number?? A Triumph number?? Reconditioned engine??
Frank
