The ignition switch is 2 years old. Factory part, but I did have to modify the steering column (ie break an aluminum tab and use a zip tie to hold a button/ switch in place.) Maybe it’s for the 98+ models. It seems to be holding. It was causing the truck to only drop down to 3rd gear.My 1997 Blazer did that and it was the ignition switch itself. Replaced with an Autozone and it failed a year later. Replaced with GM one and it is still working today (about 8 years).
The lock itself doesn't change, so the key doesn't change. Just the rotary switch part goes bad.