SUMMARY: THE 6.9L DIESEL ENGINE WAS NOT UTILIZED IN THE SUBJECT VEHICLESPRIOR TO THE 1983 MODEL YEAR.A PROPORTIONING VALVE WAS ADDED AND THEFRONT BRAKE METERING VALVE (WHICH DELAYS FRONT BRAKE APPLICATION) WASDELETED ON 1984 MODELS.FORD ISSUED A SERVICE BULLETIN IN NOVEMBER 1983RECOMMENDING THAT A 275 PSI PROPORTIONING VALVE BE INSTALLED FOR OWNERSWHO COMPLAIN OF EXCESSIVE REAR BRAKE SENSITIVITY.ANALYSIS:THE 6.9L DIESEL ENGINE INCREASES VEHICLE WEIGHT BY ALMOST900 LBS. COMPARED TO A TRUCK WITH A SMALLER V-8 GASOLINE ENGINE. MOST OFTHE ADDITIONAL WEIGHT IS SUPPORTED BY THE FRONT WHEELS.THE DESIGN CHAN-GES INCORPORATED IN 1984 APPEAR TO HAVE CORRECTED THE PROBLEM.STATUS:FINAL ETF TEST REPORT RECEIVED 6/15/87.IR RESPONSE DATED10/12/87.