I have heard that when you replace the ac compressor on a 95 Cheyenne 1500 4.3 vortec V6. That need to it with GM because OEM will not last long is this true?

That's a common misconception, but not entirely accurate. While GM compressors *were* often considered higher quality in the past, it's not necessarily true that *only* a GM compressor will last on your 1995 Chevy Cheyenne 1500. The longevity of an AC compressor depends on several factors:

* Quality of the replacement part: There are many reputable aftermarket AC compressor manufacturers that produce parts comparable to the OEM. Buying a cheap, no-name brand is more likely to fail prematurely than a higher-quality aftermarket or a genuine GM part.

* Proper installation: Incorrect installation is a major cause of premature compressor failure. Improperly charged refrigerant, leaks in the system, or damage during installation can quickly lead to problems.

* System maintenance: Regular AC system maintenance, including refrigerant checks and leak detection, significantly extends the life of all components, including the compressor.

* Condition of other components: A failing condenser, evaporator, or expansion valve can put extra stress on the compressor, leading to early failure regardless of the brand.

In short: While a genuine GM compressor might be a slightly safer bet, a high-quality aftermarket compressor from a reputable brand (like Denso, Four Seasons, etc.) can perform just as well, provided it's properly installed and the entire AC system is in good working order. Focusing on a proper installation and ensuring the whole system is healthy is far more important than obsessing over the brand of the compressor itself. Do your research and choose a reputable parts supplier.