They might be fine for 5.0's but for some reason I've heard mostly complaints from other 4.6 owners. Mine developed a leak within a week of installation. Retightening header bolts were just too much of a PITA and never seemed to get rid of a slight pulsation on the driver's side. Eventually got rid of them altogether when I changed my K-member since it required removing them or at least lifting the block just to retighten the bolts.