You would need to go with at least a 120 amp isolator. THe one I have is a sure power. Make sure you get one to fit your alternator. Some require external excitation which means you'll have to hook up a wire from an acc. source to the isolator then to the alternator, or else the alternator will never turn on. Napa auto parts sells them, but they repackage them and put their name on it. I think you will need a 12023a, which is the same one that I have. http://www.surepower.com/pdf/isolatorguide.pdf
http://www.napaonline.com/cgi-bin/nc...2&prmenbr=5806 If you need alternator adapdater wires you can buy them here. http://www.nwreg.com I got a cool in line harness that includes a 3 foot sense wire that plugged right into the isolator so I didnt have to do any cutting or splicing.