i'm not sure if i'm right with this but i use a "petrotonix ignitor" for my ignition instead of points and it works great that might be your problem and by the way the performer intake manifold is the stock one for the 390 except it is alluminum the performer rpm manifold is the upgrade (didn't know if you knew that or not i was looking at them and saw that and was surprised) and also that is a really really sick sick truck!!!! my god i wish i owned that