Ok last season bought the Merlin oval port heads from Summit and they they said they came with severe duty exhaust valves.OK so I ordered the extream from Manley laped them in and ran last season with out any problems. Took the heads to the shop for this years new valves and ordered the extream exhaust valves for them again. I called Manley to check the prices on them from what the shop said and I found that the Merlins came with the extream valves from the start.Should I feel stupid Tec .tip before you think take a magnet to the valve and if it is the extream-inconnell it will only be magnetic half way down.Owell guess I have a set of extream for 2005 season