README for ALDL information To find the ALDL datastream information for your car, start with the file index.doc. This is a text file, despite the .doc extension. In here, you can locate your engine by displacement, year, and VIN code. Once you've located it, you'll see that it's under a DATA STREAM heading. This heading represents the datastream for that engine, and the format of the datastream can be located in a different file. See below for an example. You own a 1988 Chevy C/K pickup with a 5.7L throttle body injected engine. That engine is located in the following section: DATA STREAM A33 4.3L TBI (LB4) (VIN=Z) 86,87,88 TRUCKS 5.0L TBI (L03) (VIN=H) 87,88 TRUCKS 5.7L TBI (L05) (VIN=K) 87,88 TRUCKS 4.3L TBI (LB4) (VIN=Z) 91 TRUCKS These engines all share a common datastream, called A33. The format of datastream A33 can be found in the file A033.ds