Well, I have a good feeling you won't like the 13X8 at all, it will fly the Razzel way too fast, and will have trouble slowing it down.
You may want to reconsider drilling out the prop and just use what you have untill the 13X4 gets there.
The thing about a smaller pitch is, it allows the enging to spool up quicker, thereby avoiding the hiccup at the midrange....the higher pitch 8 prop will bog the engine down in the mid range and when it does get up to full RPM will fly the plane faster than you'll want it, or it (the plane) needs to be flown.

Props are cheap enough to experiment with...Pretty much untill you get into the larger APC's....... try making notes of how each prop preforms on a given plane/engine combo.