I have a set in mine I believe are the new style . about 8 in. long still a baffle just longer than the hi perf style . with the basset T -valve I dont think I could pass a uscg test i.e. 39 inches of transom at idle under 88db . I 'm pretty sure thats the test for new boats not sure if thats the test they would use on an older boat . any how my boats pretty loud at idle , never had any problems where I boat but I'm also curious if there is any way to quiet the exhaust if I ever get tested .good luck, Jarrod