Yes they bolt on but you may need some other parts to make them work correctly. You want to make sure your pushrods are the correct length and match what your pushrod adjusters are. They are either Ball or Cup on the adjuster. Most likely your going to need new pushrods. You talking LA "Shaft" mount or Magnum "Stud" mount?
Unless you have large hydraulic cam or a solid cam they won't add much. Also, you get what you pay for, if you break a rocker or adjuster, you'll spit the lifter, loose oil pressure and smoke you motor.
They really are not a power adder. What they will do is drastically decrease valve tip and valve guide wear. You need to be careful though. There's a lot of cheap chinkesium out there. If you get some, get good ones.