HPP3, tuning w/tire heigth for 3.73 gear!!!!

[Firehawk N Wv]

I put in a GM 3.73 gear about a month ago and of course the speedo is a lil off. I have the HPP3, but as most of you know it does not have a 3.73 gear option. Only goes to 3.42 gear which came stokc in my car cuz of the Y87 package. Now I'm wanting to know what to set my tire heighth at on the programmer to get my speedo to where its 1-2 mph's off. I know it will be off by 1 or 2 adjusting the tire height. My tires are Nitto 245/50/16's all around. So if somone can help me out give me a shout. Or you guys who have a 3.73 gera could tell me what RPM you are runing at a certain speed so i can try to match that with the HPP3. Thanx guys again!