I have been gapping at about .030 on the plugs. I have been attempting to lean the SU's on the worst one of the lot, which is a 73 144 with the later version SU's that dont have any discernable throttle shaft wear to no avail. I have also swapped out the complete carb set on this vehicle once. The other part of the story is, two nights ago I swapped the coil for an Accell High output that was laying around the shop to see what happened. The idle picked up, it seemed to perk up a bit but as I found out later, burned the points out within a half an hour. As a concequence of this I changed back again and put a new set of points in. My original thought was that if there was a coil out there that may help to mitigate against this soot problem until I can find out if the gas has changed then I would try it!