Hey guys, I am new here,and this is my first post. I live in Massachusetts,and own a 78 Datsun 510 that I upgraded to 38mm round top SU carbs. The car is now running,but one carb is running richer than the other one,and I have turned in the large nut on the bottom of that one very much,and the plugs on those two cylinders are still sooty,and darker than the rear two which seem pretty good. I have the Z-therapy video,but I am still lost. Anyone in the New England are willing to come help me out? I know this isn't a Z-car,but it has to be pretty much the same. Thanks in advance. Chris