I just purchased a project boat, 25' 1978 Apollo with twin 120 engines. I have a leak from from the rubber exhaust hose that connects the exhaust riser to the intermediate housing. I have found the Omc part number 0909371, but when I purchase the part the new rubber hose is different than the original. The original has a ridge on the inside of the rubber hose that fits in a groove on the exhaust pipe. The question is, did they remove this ridge on the hoses and use a straight hose, or am I getting the wrong part. Thanks for any help in advance.