I found a little trick in a book you can do to modify your stock one down to 168 deg for a quarter. You need a 1/8" brass or a brass screw, file it down to .090 inch. Remove your stock t-stat. On the back side of the t-stat push down and twist with a pair of pliers to release the spring, pull all the goods out keeping them in order. Then place the spacer down in the small hole and reasemble. Every .0036 inch is 1 deg. I did mine that way. I filed a brass 1/8" screw down to .061 which 180 deg. works great.