Just a quick question are P11 push rods okay for an early ,(1962,I think), Atlas engine?
It all depends on the length of them. After engine and frame numbers 125871 the pushrods were shorter and the valves longer. Before 125871, the pushrods were longer and the valves shorter. It all depends on the length of the ones you want to use, as the P11 series went from engine and frame number, 121007 to 129145.
My Alas engine is 20/P/105713, 1962 unit? I will measure the Push rods, short ones, 7" 5/8ths and the other 8 5/16ths long ones. I also have a set of new valves, an 23166 Atlas head.
I have the Atlas engine for a Street Scrambler project, I was going to put it in a BSA frame!