my car is reading half the rpms it should be reading. it will tach out at 3700 rpm while I'm positive its more like 7800 rpm so its perfectly reading half the rpms it should. The cars setup is a common 6-bolt swap running a green top cam angle sensor and tuned off an SAFC. I guessing that the cam sensor is the culprit but wanted some opinions, so any help would be very much appreciated.