These mid-length BlackHeart headers are for 1987-2006 Jeep Wrangler YJ/TJ/LJ with LS engine. They have 1-3/4 inch primary tubes, 2-1/2 inch collectors and are built from lightweight 304 stainless steel. The tube geometry and collector outlet positions are specifically designed for this application to maximize component compatibility, clearance and suspension travel. They work with BlackHeart Y-pipe and engine mounting brackets to provide a simple engine swap solution.