Identifying the correct 10-speed automatic core for your powertrain swap can be tricky. General Motors uses a global sequential numbering system for its service assemblies and frequently changes prefixes across production years.
Use this master guide to decode GM factory tags, identify your core instantly, and avoid buying the wrong transmission.
🔍 The 2-Letter Broadcast Code Shortcut
Because GM creates new codes constantly based on vehicle year, engine, and tuning, there is no single master list of every 4-character broadcast code. However, you can identify whether a transmission is a 10L80 or a 10L90 just by looking at the last two letters of the big, bold 4-character code on the white barcode sticker.
- Ends in
KJ,GJ,FJ, orCJ→ 10L80 (Lighter-Duty) - Ends in
MJ,NJ,PJ, orPM→ 10L90 (Heavy-Duty / Commercial)
📦 Salvage Yard Cheat Sheet
When hunting through salvage networks, use these common broadcast codes to quickly filter your target transmission family.
🔴 10L80 Broadcast Codes (Avoid for Max-Strength 1-Ton Swaps)
These units are paired with 5.3L V8s, standard 6.2L car engines, or light-duty 3.0L Duramax diesels:
02GJ, 04FJ, 06CJ, 1BKJ, 1XKJ, 2BKJ, 30KJ, 86KJ, BKJX
🟢 10L90 Broadcast Codes (Target for Heavy-Duty & High-HP Swaps)
These are ultra-strong cases paired with supercharged LT4 V8s (ZL1, Cadillac Blackwing) or 6.6L L8T Gas HD truck engines:
8LPM, 9LPM, KPMX, LPMX, MPMX, NPMX — Common on early high-performance units
10PJ, 11PJ, 20PJ — Common on newer 6.6L gas HD trucks and commercial cargo vans
🔢 GM Part Number Sequencing
If you find a code not listed on our cheat sheet, look directly below the 4-character code for the 8-digit GM part number string.
Standard Production Eras (2017–Early 2020s)
The vast majority of first- and second-generation 10L80/10L90 assemblies fall into these three primary sequence blocks:
240XXXXX-
242XXXXX— e.g., standard GM Genuine Parts 10L80 units 244XXXXX
Modern Replacement Sequences (2024 and Newer)
Third-generation internal updates featuring modern, safety-updated valve body units commonly start with:
25XXXXXX196XXXXX
GM Performance Crate Program Assemblies
Standalone transmissions ordered directly from the Chevrolet Performance Crate Catalog bypass dealership service sequences entirely. Official custom-swap packages utilize 19... sequences:
-
Part # 19541013: SuperMatic™ 10L90-E -
Part # 19436467: LT4-matched 10-speed packages
🛠️ Swap Takeaway: How to Verify Your Core
Never rely solely on the first three digits of a part number. To guarantee an accurate match before fabrication or tuning begins:
- Locate the white factory tag on the transmission case.
- Document the full 8-digit part number string.
- Document the large, bold 4-letter broadcast code.
Disclaimer: Wicked Wrench Motorsports Disclaimer: The technical information, part numbers, and compatibility guides provided on this website are for general reference and educational purposes only. Automotive swaps, custom fabrication, and powertrain modifications carry inherent risks. Wicked Wrench Motorsports is an independent automotive service provider and is not affiliated with, sponsored by, or endorsed by General Motors or Chevrolet Performance. While we strive for absolute accuracy, part numbers and manufacturer specifications can change without notice. Always independently verify component compatibility, safety specifications, and vehicle regulations before initiating any mechanical work. Wicked Wrench Motorsports assumes no liability for vehicle damage, personal injury, or component failure resulting from the DIY use of this information.