There are four (4) unique cylinder heads for Gen V LT. 5.3L engines have smaller intake port openings, smaller valves, and smaller chambers. 6.2L have supercharged heads and non-supercharged heads with unique valves, chamber volumes, and intake bolt patterns among those. The 6.6L L8T uses modified 6.2L non-supercharged heads with HD exhaust valves and extra holes drilled in the deck. Here are a few key visual queues to know which heads you have:

Intake Port Openings and Bolt Locations - 5.3L heads measure around 2.04" tall while 6.2L and 6.6L heads measure around 2.11" tall. On LT4 and LT5 supercharged engines, the manifold bolt holes are raised to the top of the port opening while all other intake bolts remain around the center of the port.
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Steam Ports in Deck Surface - L8T heads have extra holes drilled in the deck surface between chambers, all other heads are not drilled here.
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Chamber Shapes and Valve Diameters - 5.3L chambers measure around 3.8" across and have a small quench or eyebrow above the spark plug. 5.3L intake and exhaust valves measure 1.93" and 1.55", respectively. 6.2L and 6.6L heads all have 2.13" intake valves and 1.59" exhaust valves. All measure 4.08" across. Notice the LT4/LT5 supercharged heads have an open chamber above the spark plug while non-supercharged 6.2L and 6.6L heads have a distinct eyebrow above the spark plug.
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Early vs. Late Injector Bores - 2014-2021 heads are drilled for 7.5mm injector stems while 2024+ heads are drilled for 6.0mm injector stems. 2021-2024 heads could be either as this was a rolling change implemented by GM and should be measured before buying service parts.
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Summary
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