The LA 46 should turn at about 11,000 with an 11X5 APC prop, give or take a few hundred rpm depending on altitude, humidity, temperature, etc. I always use a tach to set the high speed needle at the beginning of the day, setting it to peak rpm -300 rpm to the rich side. Been running it for 3 years without a dead stick.

When it unloads in a dive at full throttle, you'll probably approach the 14k-16k range. The 11x5 is my prop of choice for the LA 46, as it gives a good optimum for thrust and speed. Its actually faster at full throttle than my SPAD Debonair likes.

Good Luck.

Brad