Cal-Van Tools' GM Thermostat Wrench, No. 751, can work on GM 3.1 and 3.4L V6 engines. Thermostat replacement forces the technician to remove the thermostat housing. In these applications the bottom housing bolt is almost inaccessible without removing other parts, until now. The wrench with its unique shape and design allows users to remove and install the housings in a fraction of the time it currently takes. The wrench is a 13 mm, 12 point with special bends specifically for GM V6 thermostat housings.