I have purchased new 3:55 ring n pinion gears (in addition to the complete rebuild kit) for my stock 1948 Chevy 3100 to replace the current 4:11 gears. I would like to cruise a little faster than 45mph but also reduce the rpm on the 216 while cruising. This upgrade is more than my expertise so I am going to have to have it done professionally. Should most shops be able to do this or should I ask specific questions to decide you to use and what would be an average price for doing it? I am in the Houston, TX area if there is somebody you would recommend.