I have lots of noise under the right side valve cover and the car has very little power. Is it possible that if the lifters are not adjusted properly?

 

You don't adjust the lifters. You adjust the amount of preload placed on the lifters. You might have a collapsed lifter and if that's the case, the heads have to be pulled and the lifters replaced. What are the specs of your cam and valvetrain setup? Stock lifters, rockers?

 

lots of noise like what? rattling and ticking? maybe its a busted rocker arm or rocker arm bolt. just pull the valve cover and see if you can find anything