Too much cam?
I partially agree with Don... That cam is fine. It's a tuning deal. You say adding timing helped. You added initial. Have you checked any of the distributors you installed for the rest of the advance curve? If indeed 25° "fixed it" (wheel spin is a good problem to have and a whole seperate discussion) then I would be looking at what the mechanisms are doing as the throttle opens. Have you tuned the vacuum advance? What rpm does the centrifical start to advance? What is your idle rpm?