The Performance On Line kit is listed for a 3100, I notice. I suppose that it would work for 3800 trucks if the master cyl size was right but it certainly wouldn't be a bolt-on-and-forget-it. There would be math involved. Also I wonder if the small diameter vacuum chamber would provide enough boost. I went to a 2-ton hydrovac after towing a 1500lb trailer with 2,500lb. camper aboard through Vancouver B.C. rush-hour traffic. My right knee was pretty sore. My typical gross is ~9,000lb nowadays so I'm not anxious to give up any boost. But my front drums are worn so I need to do something. New pickups are about 50-60 grand if you get one with a similar payload and CGVWR so there's some incentive to work on the one I've got.
