The pistol grip arrived for the 1970 model year in the performance B bodies. The pistol grips for '70 were a one year only style.
For '71, the bucket seat B Body performance cars got the same handle that the E bodies had. Plus, they got a unique handle for the bench seat B body cars.
I am not sure what the last year of the pistol grip was. The B body as we know it ended in 1975. Did the pistol grip make it that far?
If any of this is inaccurate or incomplete, I am sure it will be corrected.