Ya they used to spar all the time.

Towards the end of his career (such as his training camp for the Oscar fight), Pernell trained with guys like Zab, Gatti, Vargas, etc.

If only Zab had paid attention to what Pernell did in the ring, he might've been a better fighter. When Zab first turned pro, he was billed as "Pernell with power." Only problem is that he never worked on any of the skills that made Pernell great, he fell in love with the "power" part.