Can't really say specically, but since a solid roller can have faster ramps with more area under the curve with less advertised duration the improvement could be substantial. This all depends on air flow of the heads, intake and exhaust though. Along with other factors. If I were you and looking for all you can get out of the combo I would talk to several different cam grinders and get their suggestions before making a decision.

Nice running car you have already, hope you can find what you're looking for. Pics would be nice!!!