I changed my faulty impco model j regulator to a impco cobra that the local parts store said was the replacement. After starting it up it ran beautifully except it didn't have any power. It couldn't make it up a hill that we drive it over regularly. Its as if i am only pressing the pedal down half way. I noticed the old impco regulator says "w.c..2 lbs" the new one says "w.c..08 lbs" I brought this to the attention of the parts store but they insisted that it was the right part, I even talked to the service manager and he said it was ok.

My question is would this difference cause the problem i'm having? thanks