I agree, i just bought a new Speed Pro with close to the same #'s. 287 with .468/.490, but with 110 lobe seperation for my street Elky. i had no vacuum with the .520/296 cam and my brakes was at best 1/2 petal and scarry. The cam i bought is going on a 350 with trick flow heads and a duel plane with a 750 vacuum secondary, stock GM short blk.
I would say good choice
JMO
Zip.