Have a read of this thread. It is for B20E so 4 cylinders instead of 6 but the fault might be the same. Rubbing block wear.
https://forums.swedespeed.com/showth...int-adjustment
If the B20E fires in pairs the B30E may fire in threes. The B20 dizzy has 2 sets of points against the B30 having to have three sets of points if the B30 had to fire in pairs. I've not looked at the parts book but I think they both have 2 sets of points. You'll have to check.