That shouldnt be a big problem to fix.I just rebuilt a c6 and the park didnt work.Here are the two things to look for.Take off the tail shaft section.You will have to remove the drive shaft and the rear trans cross member .Then the speedometer cable then the bolts that hold on the tail shaft cover.Now look on the drivers side and you will see a little heavy built piece that travels from the left to right that goes into the park gear.If it is broken you only have to remove the pin that is holding it and install a new piece and put the pin back in.The pin is,I forget,I think it is a 1/2" dia. pin and there will be a little long spring that fits there to hold it back to keep it from going in gear when it is not in park.Now the other thing to look for is a e clip.You have to pull the pan and you will see a rod that runs from where that other piece is that I had talked about and goes up to your shift arm on the inside there.Put that rod back on the shift arm and put that e clip back on.If you have small hands you can get that clip back but if you cant get it you will just have to remove the valve body to get to it.I had some long needlenose pliers and I got mine back on without removing the valve body.
