I recommend Hatch and Sons in Wayland Mass. For you they are within an hour down 128 and then shoot west on Rt 20 right to the Wayland/Sudbury line. I just used them for the first time last week and they nailed my cars "stall on quick start from stop problem" (a loose crank position sensor) that had stumped two MB dealers that I had taken the car to. (and cost me big $$ for misdiagnosis to boot). The H&S techs appeared to know these cars well.... Just my experience...your mileage may vary.

__________________
Matt
____________________________
92 400E 128K
99 GMC YUKON 88K