Engine - Production Changes/Interim Product Updates
File In Section: 6 - EngineBulletin No.: 77-61-08
Date: March, 1997
INFORMATION
Subject:
1997 Trucks with 6.5L Diesel Engine Interim Product Updates
Models:
1997 Chevrolet and GMC C/K, G, P Trucks
with 6.5L Diesel Engine (VINs F, S, Y - RPOs L65, L56, L57)
Built after January 13, 1997
with the VIN Breakpoints:
The following product updates have been implemented on the 6.5L diesel engine for mid-production in the 1997 model year. This information is listed as a brief overview. The updates are an enhancement to the 1997 6.5L diesel engine.
# 1 Compression (Fire) Ring (All Applications)
The material of the fire ring has been changed to moly-carbide to increase durability.
PCM Calibration Update (L56 C/K Only)
The vehicle PCM calibration was updated to allow enhanced EGR diagnostics.
PCM Calibration Update (L65 C/K Only)
The vehicle PCM calibration was updated to allow greater horsepower (195) and greater torque: A/T @ 430, and M/T @ 420.
Emission Labels (L65 C/K Only)
The labels have been updated to reflect the increase in horsepower (195) and torque (420 OR 430).
Clutch and Clutch Bolt Lock Washer (All M/T Applications)
The clutch was updated for the increase in horsepower and torque. A lock washer has been added to the clutch retaining bolts.
Oil Cooler Line Connectors (C/K and P)
The fittings have been changed from 1/2" ID to 5/8" ID to connect to the larger oil cooler lines. G van has these parts from MY97 SOP.