i know that the push rods are a12 ones as i tried to fit a14 ones when changing the head and the where to long and i still had a spare a12 pushrod laying around and i measured it up to the new ones and it was the same lenght

when i tightened the rockers i reset the crank to t.d.c to do the cam timing so maybe it was the valves opening up againts the pistons

and by the way who ever said that you cant put a camshaft in while the engine is still in the engine bay is wrong it was easier than having to take the engine out