how much hp, tq will 8.25 take

If you start getting your car to hook hard, I would say the 27 spline axles are going to fail. If you go with the BB stroker I would consiter a Dana 60 or at least a very well built 489 or 742 8 3/4 with good components like Moser or Strange engineering with 35 spline axles. But thats me I tend to lean towards overkill. " Build or buy the best and you'll never be disappointed"