Hey guys, I bought a GT turned Terminator swap car and have a weird issue. And before it gets asked the car has a 03 gauge cluster, T56 and the whole she'bang. The cars speedometer doesn't register a speed until 40-50 mph and the needle starts reading 10+ mph, and at 3k rpm in 6th at basically a real 90mph the car reads 25-27 mph. I replaced the VSSensor and took out the old one(which looked new as well), and still have the same issue. This and the theft light blinking during warmup is the only 2 issues the car has. Trying to figure this out before tearing the dash apart and taking the cluster out. Any ideas as to what I should check next? Thanks