While the charts are somewhat usefull, they are very generalized & make no distinction for engine characteristics or airframe types -- prop selection is not that straighforward. In addition to the type & size of engine, it also very much depends on the type of aircraft in use & the nature of the in-flight activities that you want to enhance or suppress.


For example, a TT .61 Pro or FX .61 will pull a lot more prop than an LA .65 -- and a 12-5 on an LA .65 & a big trainer would work OK, but could be a really poor choice for a TT Pro on a clean, speed-oriented sport flier.

You need to tell us what specific K&B motor you have, what the model is & what kind of flying that you expect to do with it.