Hi thanks for the replies!
Noisymime your solution sounds good, but the problem is the engines we fit crank gear patterns rarely match the cars original crank gear pattern. For example we fit an engine with a 36-1 gear into a car that used a 60-2 setup. The other problem is most cars that uses a VR sensor use ground as the reference voltage and the aftermarket ECU uses a 5 volt reference voltage. So no go unless you use extra hardware and then we still have a problem if the gears don't match up.
MorganS I have seen those units, but I love DIY and I love saving money even more!