I think Pac gets another boxing lesson (like Mayweather gave him) at 135. Pea is simply too skilled and too slick for him.
Sweet Pea by close UD. Pea didn't have the punch, or size, to keep Pac off him or keep him honest, but his defense was top notch. @ 135 Pac still had lightning quick punches and threw combination like few did. He would land on Pernell at times. And with force. But I believe Pernell's amazing defense and accuracy would eventually be too much.
Yeah I'd favor Whitaker in this. I think Pac definitely has some quick awkward movements that could cause Whitaker some problems, but I think Whitaker was just too good to be caught, especially at 135. I do think 135 was probably Pac's best weight and age, but I think he was more complete with his skillset at 147. Plays out similar any weight class though.
Pac has a better chance at 147, where Pea didn't have as good legs, but in the end Whitaker schools him anyway. Especially at 135, where Whitaker is arguably the best lightweight ever. But watch the Ramirez rematch. That Pea beats anyone since, and almost everyone before.