This document aims to clarify the differences between early and later flywheels and flexplates used in 6.2L and 6.5L diesel engines. By sharing this information, we hope to assist our customers in making informed decisions and avoid potential compatibility issues.

The 139-tooth flywheel, with an outside diameter of approximately 14.15 inches (often listed as 14.140"), was utilized throughout the entire production run of the 6.2L diesel engine, spanning from 1982 to 1993.

• Outside Diameter: 14.14" to 14.15".

• Tooth Count: 139 teeth.

• Engine Balance: External (weighted).

The automatic flexplate for the 6.2L diesel engine shares the same outside diameter and tooth count as the manual flywheel. For the 1982-1993 6.2L diesel, the flexplate specifications are as follows:

• Outside Diameter: 14.13" to 14.15".

• Tooth Count: 139 teeth.

• Engine Balance: External (weighted).

For GM vehicles equipped with the 6.5L diesel engine from 1993 to 2001, the standard manual transmission flywheel typically features 138 teeth and has an outer diameter of approximately 14.25 inches.

• Stock Dual Mass: 138-tooth, 14.25" outer diameter.

• Diameter: Generally 14.25 inches.

• Tooth Count: 138 teeth.

The most common specifications for a 6.5L diesel flexplate, typically paired with a 4L80-E transmission, are as follows:

• Tooth Count: 139 teeth.

• Outer Diameter: 14.25 inches.

• Balance: These engines are externally balanced, meaning the flexplate will have a counterweight welded onto it.

For further information or inquiries, please feel free to contact us at support@quadstartuning.com.