how much would get cost to replace the two rear struts on a 87 GXL?
let me know thanks.

 

depends what you are looking for... if you're looking for cheap shocks proably around $100 pair. good ones around $200 install isn't too hard either.

 

also the rear hub is broken( no tthe hub cap) but the hub the tire is sitting at an angle but it can be moved around if it was off the ground. how much would it cost to get one of those?

 

Don't just replace the rears. Make sure you replace all 4 at once. If the rears are shot, then the fronts are soon to follow. Plus it will unbalance your cars handling and probably make you have an oversteer problem because the rears will be newer and more resistant to movement cause a stiffer rear suspension. Also about your hub. If your hub has movement to it, then your bearings might be shot, as opposed to your hub being broken. If you can grip the top of your tire and push and pull and feel movement, its probably the bearings.