need to buy ls7 lifters

Buy them new. SDParts | GM Performance Parts, GM Crate Engines, GM Goodwrench Crate Motors and Performance Crate Engines - 1-800-456-0211 has them for a good price, I just picked up a set myself.
GM Performance Parts 12499225 - Lifter Kit, Gen III Engines, Set of 16 | SDParts - 1-800-456-0211