how strong is a 8 1/4 rear end
 

what is the most hp that you can have will still using a 8 1/4 rear end. Are there performance parts for a 8 1/4 that can handle lets say 450 hp.

What is the axle in?

I wouldn't put more than 300 to an 8.25 rear axle. You can get spools, lockers, posi units, upgraded axle shafts for them, but you would be better off to install a 9 in rear, 8.75 rear, 9.25 rear or a D60 rear axle

so in other words its not worth building up a 8.25 rear end. your better off going with something else cost and long term wise?

correct. I had an 8.25 in the back of my 01 dakota and I pulled it out because the bearing were toaste after 62,000 miles. I swapped in a 9.25 out of a durango R/T and never worried about it.

i have a stock Dana 60 in my car
what horsepower is it good up until?

depends somewhat on the spline count. if its a 19 spline then I wouldn't put much more than 400 to it without upgading the axle shafts, carrier, R+P and bearings. If its got the 29 spline shafts (i think) then i wouldn't worry about it unlesss your building a strong motor.

I have seen a lot of weaker, small axles live under huge tires and/or lots of power. Then again, the people driving them were not beating on them. I've also seen guys tear apart the R+P Iin a D60 with a set of 35s and a stock V8 in a truck.

It all depends on how your going to be driving it. If you take it easy and just like to cruise (maybe hammer down once in a blue moon), then you shouldn't have a problem. If you like to take it to the strip every month or more, then spend the extra money in building an axle that is designed to take it.

oh, ok, then it's fine for me.