If you broke in your 46 and like the way it runs break in the GP just the same. These little engines are pretty much bullet proof anyways.
This was my first engine and had multiple lean runs,a few dirt naps,broken parts,covered in jb weld and no controled break in at all. After all of this, once I learned how to tune it properly and set up a feul tank it ran like a clock,and still had lots of compression. For what it is,this is a powerfull little unit,but don't expect it to put out like the PRO 46.
TT 42 GP Master Airscrew 11 5 11,500 rpm
APC 10 6 12,100 rpm