Race fuel is fine in two strokes. It will help make a little more grunt by allowing more timing and compression. However, you need to make sure the head is cut and re chambered to burn it correctly or even get a cool head with correct domes for your set up. On that note, have the domes/head cut for the stroker and don't bother with a spacer plate at all.
Also, are you porting for this combo? The crank will be useless with out at least some mild port work to compensate for the stroke.