5750 from a 22x10. I tried just about every trick I know but it was not possible to get a singe rpm more out of the engine.
On the way home I had another Idea. My ring collector lacks a preasure nipple and to make things worse I had blocked the ventilation nipple after swapping the engine for the 400 on the stand. I am sure I am loosing some RPMs there. Also want to try a 22x10 APC because on the 400 the 20x8 Wooden Prop gives 800rpm less than the APC Prop with the thinner blades. I thought of something else in the car too. I am not qite sure if that FW190 Spinner Backplate with those litte blades isnt eating power too.