No, but most times...especially if the combo wants some air, the spacer will add about 10HP and improve both HP and TQ curves when used on a dual plane.
I'm waiting for the OK to post our other results from the topend swap...
If it was a longer stroke in relation to the port/intake I'd think that would be the case but it should not be wanting for air with that intake and carb. I'd be curious if that would have helped the low end and peak rpm.
