General Motors (GM) truck motors are known for their durability, reliability, and performance. Whether you're looking to purchase a new or used GM truck engine for your race car build, it's important to know how to identify the motor to ensure you're getting the right one for your needs.

One way to identify GM truck motors is by their casting numbers. The casting number is a series of alphanumeric characters that are usually located on the engine block or cylinder head. It's a unique identifier that tells you the engine's make, model, and year.

Here's a breakdown of some of the most common GM truck motor casting numbers and their corresponding year, make, and model information:

1. 3970010 - This is a small block V8 engine that was produced from 1969 to 1980. It was used in a variety of GM trucks, including the Chevrolet Camaro, Corvette, and Nova.
2. 14015445 - This is another small block V8 engine that was produced from 1975 to 1985. It was used in the Chevrolet C/K truck and the GMC Sierra.
3. 12568758 - This is a small block V8 engine that was produced from 2002 to 2007. It was used in the Chevrolet Silverado, GMC Sierra, and Hummer H2.
4. 12551358 - This is a small block V8 engine that was produced from 1999 to 2007. It was used in the Chevrolet Silverado, GMC Sierra, and the Cadillac Escalade.
5. 12681432 - This is a popular small block V8 engine that was produced from 1987 to 1995. It was used in the Chevrolet C/K truck, the Chevrolet Caprice, and the Buick Roadmaster.
6. 10243880 - This is a small block V8 engine that was produced from 1996 to 2002. It was used in the Chevrolet Camaro and the Pontiac Firebird.
7. 10243880 - This is a small block V8 engine that was produced from 1996 to 2002. It was used in the Chevrolet Camaro and the Pontiac Firebird.
8. 10243880 - This is a small block V8 engine that was produced from 1996 to 2002. It was used in the Chevrolet Camaro and the Pontiac Firebird.
9. 10243880 - This is a small block V8 engine that was produced from 1996 to 2002. It was used in the Chevrolet Camaro and the Pontiac Firebird.

Here's a more in-depth breakdown of how to identify some of the most popular GM engine types, including the LS3, LS7, L76, L9H, L94, L99, L77, LSA, LS9, LH6, LY5, LY6, LC9, LFA, L98, L20, LZ1, L96, LC8, L92, LH8, LM7, LR4, LQ4, LQ9, LM7, L33, LS2, LMG, L59, LS1, and LS6.

1. LS3 - The LS3 is a high-performance small block V8 engine that was produced from 2008 to 2017. It has a displacement of 6.2 liters and produces up to 430 horsepower. It was used in the Chevrolet Corvette and the Chevrolet Camaro SS.
2. LS7 - The LS7 is a high-performance small block V8 engine that was produced from 2005 to 2015. It has a displacement of 7.0 liters and produces up to 505 horsepower. It was used in the Chevrolet Corvette Z06.
3. L76 - The L76 is a small block V8 engine that was produced from 2007 to 2009. It has a displacement of 6.0 liters and produces up to 367 horsepower. It was used in the Holden Commodore and the Chevrolet Caprice PPV.
4. L9H - The L9H is a small block V8 engine that was produced from 2007 to 2013. It has a displacement of 6.2 liters and produces up to 403 horsepower. It was used in the Chevrolet Tahoe and the GMC Yukon.
5. L94 - The L94 is a small block V8 engine that was produced from 2009 to 2013. It has a displacement of 6.2 liters and produces up to 403 horsepower. It was used in the Chevrolet Silverado and the GMC Sierra.
6. L99 - The L99 is a small block V8 engine that was produced from 2010 to 2015. It has a displacement of 6.2 liters and produces up to 400 horsepower. It was used in the Chevrolet Camaro SS.
7. L77 - The L77 is a small block V8 engine that was produced from 2011 to 2017. It has a displacement of 6.2 liters and produces up to 361 horsepower. It was used in the Holden Commodore and the Chevrolet Caprice PPV.
8. LSA - The LSA is a high-performance small block V8 engine that was produced from 2009 to 2015. It has a displacement of 6.2 liters and produces up to 580 horsepower. It was used in the Cadillac CTS-V and the Chevrolet Camaro ZL1.
9. LS9 - The LS9 is a high-performance small block V8 engine that was produced from 2009 to 2013. It has a displacement of 6.2 liters and produces

As an addition, here are some of the most common casting numbers associated with the GM engine types mentioned previously:

1. LS3 - 12621766 or 12623967
2. LS7 - 12623968 or 12621214
3. L76 - 12598832 or 12595365
4. L9H - 12623968 or 12638502
5. L94 - 12638502 or 12617655
6. L99 - 12625455 or 12638530
7. L77 - 12644698 or 12632260
8. LSA - 12621766 or 12670278
9. LS9 - 12623968 or 12680457
10. LH6 - 12568758 or 12572035
11. LY5 - 12584724 or 12584725
12. LY6 - 12699784 or 12677836
13. LC9 - 12581769 or 12621234
14. LFA - 12625437 or 12638502
15. L98 - 14088526 or 10066036
16. L20 - 12622189 or 12630084
17. LZ1 - 14088548 or 14088549
18. L96 - 12677741 or 12638502
19. LC8 - 12584381 or 12584379
20. L92 - 12691358 or 12623968
21. LH8 - 12572035 or 12570460
22. LM7 - 12561168 or 12551358
23. LR4 - 12550592 or 12550553
24. LQ4 - 12551364 or 12551397
25. LQ9 - 12561184 or 12561168
26. L33 - 12551397 or 12558110
27. LS2 - 12568952 or 12569494
28. LMG - 12629263 or 12691672
29. L59 - 12580426 or 12580999
30. LS1 - 12561168 or 12559378
31. LS6 - 12561184 or 12561168

It's important to note that these casting numbers are not 100% definitive, as there can be variations in the casting numbers depending on the year and model of the engine. Additionally, some engines may have multiple casting numbers associated with them. The casting number can be found on the engine block, typically on the passenger side of the engine near the rear.

In conclusion, identifying GM truck motors can be tricky, but knowing the casting number can help you determine the make, model, and year of your engine. By using this information, you can ensure that you're getting the right motor for your GM truck, whether you're looking to purchase a new or used one.