Is it too soon? Personally, I think Spence has the tools to win this one. The height and reach would be problematic for Manny, and Spence has the ability to counter the openings he leaves.
I think Spence is too big. But more than big, he's a PHYSICAL fighter, and that's ALWAYS been a problem for Pac.
The height and reach would be too much for Pac to overcome, even with Spence's own defensive holes. I think Spence keeps Pac on the backfoot all night and slows him down big time with body shots.