hi jeffrock, nice to see another p5 owner
the temps should be around 200-230°F to ensure a long lasting engine maybe even 240 under heavy racing
to use 30% nitro it is recommended by novarossi to add a .1mm head shim, there are people using 30% without adding any shims without any problem at all, if you go 30 i would suggest getting some c7s plugs in case you experience pre-ignition
about break in you should give a look in the rb forums, there's some detailed info about break in a top notch engine like the p5
by the way, what car are you running your engine?