Installed a G8 drivetrain in a 68 Camaro with a Speartech computer,upon fire up the car ran but trims were about 20% off because we built a custom intake. Made changes at the time and car seemed to be fine. About a month later after the car was finished with paint etc the car set a code P0106, diagnosed this as a pcm problem and the local dealer also diagnosed it as the same and sold us a new ecu since we are trying to deliver the car. The new ecu had a 6 cylinder operating system on it so I ended buying another vin code because the vin and operating system mismatched. I performed a full flash with the original tune that was on the speartech from my very first read and everything seemed to be normal. the car started and ran as it did on the very first fire up (20% off). Tried to flash with a 20% correction and it it said the vin was missing but operating system was still correct. I changed the vin which came back successful and then performed a read and it came back with correct operating system and vin. Tried to flash but now it is missing a serial number and wont write and when I try to read it errors out and asks me to try to read by unchecking "high speed" but I cannot uncheck high speed?