The problem with the tach is only a display problem. What i mean by that is.... when i plug my lap top into the aem ems the rpms are reading perfectly. Some where between the ems and the gauge cluster the signal is getting messed up. So i took out the cluster and found the speed sensor wire that controlls rpms had been spliced into and had part of another wire that had been cut hanging off it. So i removed what was there and crimped in a new wire. It helped because now i can go to 7K at least and sometimes it doesn't do it , but sometimes it still does. I'm going to try saudering the wire in and see if that does it. By the way, I'm running the msd 7 digital with the hvc coil and a new distributor. ( those are definitly not the problem )
thanks for the reply...