Eklka say's that ther shocks got more travel than stock, I don't see why u can't use them with a lift cause they are sort'a custom. A lift is a sot of shock extension where as I don't know about a perflex. It's elakasuspension.com and they are one another web site I found on this page. Thank God for George Dubya cause that Canadian$ keeps going UP.Victory in Afganistan.
Cory