Transmission swap

Hello, the Trailblazer was not available until 02 and had a 4.2l engine which had a bell housing design on the transmission that would not work with your truck.

2000 Blazer had the 4.3 which had a transmission with bell housing design that will interchange with your truck as long as you have the 4l60e which most did. An easy way to tell is counting transmission pan bolts. The 80e has 17 while the 60e has 16.