I've got a 150 Ocean Pro, 96 model Evinrude. Went down to the local boat fixin' place and they are wanting to charge $10 a pop for NGK bpz8hs-10 spark plugs. He said anything wih a z in it was expensive and this motor required the "z". I looked and Champion has several recommended. QL77's, QL78's and 5939's. Anybody got the lowdown on this. I really don't feel like paying $60 to change my plugs.