Once upon a time I wrote some software for the GMECM list members that would run from a web interface to allow you to lookup a GM BCC code. It would return relevant information such as the year, make, model, engine, ecm#, trans type, and more. It was a handy application and it actually started getting so many hits that it was threatening to crash the server it was on. Long story short, I killed it to due to abuse. I've offered to work with a couple of site owners over the years to get it back up but there really wasn't any interest, so it's still "resting." I'm wondering if there's interest here. Here's the data it would output for the BCC BJYK:

/BJYK/


***Found!!!
BCC year is 1995

BCC= BJYK0096 Scan id= 0335 Part number= 16200094
Release date= 12/22/93 Engine size= 5.7 Trans Type= Auto trans
ECM/PCM: PCM #16197427
Used in trucks: GMC
Possibly used in:
C1500,2WD,1/2 TON C1500,2WD,1/2 TON C2500,2WD,3/4 TON
C2500,2WD,3/4 TON K1500,4WD,1/2 TON K1500,4WD,1/2 TON
K2500,4WD,3/4 TON K2500,4WD,3/4 TON

Options:
With GU4 AXLE, REAR, 3.08 RATIO
With GU6 AXLE, REAR, 3.42 RATIO
With L05 5.7L GAS 8 CYL (5.7K) V8 TBI
With M30 TRANSMISSION, AUTOMATIC 4 SPEED 4L60E ELECTRONIC
With NA5 FEDERAL REQUIREMENTS
Without NM8 EMISSION SYSTEM, LEADED FUEL