What is the diference between the Sierra head gasket and the OMC head gasket other than the price? Is OMC worth the extra 10.00? I bought as old locked up 1980 7.5 Johnson motor and got it free and it seems to run good with 95# and 92# compression but I used the old gasket just to check it and now that all "seems" ok would like to put a new head gasket in. Thanks for any info! Jim