My 12.9 493 with ported Edelbrock heads, .660 roller and flowed BG dom. on a Team G made right at 650 hp and torque. Peak torque was right at 5,800 so I would shift the 3 speed at 6,200 which was the quickest the car went. Shifting any higher would slow it down some. I would imagine yours should make a little less and 625 seems about right. Some guys on here go pretty quick with large, solid cams. I would just put a roller in it now if it were mine.