Good deal, we now have two pictures that illustrate why little details make or break advice.

The attached picture shows a Skybolt that's completely stock, right out of the ARF box. It's been jacked up in the rear so that the prop is square to the floor. It's got the suggested propeller on it for one of the suggested engines. The prop is a 13" prop and the engine is an OS61 and the spinner is the one that came in the ARF box. (Pay no attention to the person behind the curtain holding the tape measure.)

One magazine always reports a special measurement when they do ARF reviews. They report the prop shaft to floor distance. That gives readers a feel for how big a prop the airplane can swing without cutting grass or chipping off on the pavement. If you look at the attached picture the tape shows that measurement would be just a bit over 8-1/2" for that ARF as it was assembled with the components that came in it's box. If you look, you can also see the angle of the unmodified stock gear legs as they come from the mfg. Keep in mind that gear flexes on landings and usually flexes a bit less on takeoffs, depending on how bumpy the runway is.

That setup gives that prop about 2" of clearance to a tile floor.

I've got a couple of airplanes with that prop clearance over the pavement runway at one field. When I fly them at the grass field, they start to turn green. The last few days, they've also been turning the color of red clay. They've been shattering dirt plugs that're scattered around in the grassless places that're all over that field. You always need to take your flying conditions into consideration when deciding on prop clearance. And a LOT of other small details.

Hope all the pictures and discussion have covered most of the important details and this was helpful.....