I'm reading a great article in Collectible Automobile (Aug 2006) 1974-1978 Chrysler and Imperial: Changing of the Guard. In an effort to increase gas mileage...In 1977 and up, Chrysler used thinner side glass and sheetmetal that saved 6 lbs and also saved another 4 lbs via front frame reductions. 1977 the velour seats were trimmed more conventionally losing their expensive to make loose-cushion. No change in the leather cushions. Customers complained about the 1977 velour cushions and they were returned back to the former cushions for 1978. The 78 NY'er also had pinstripping on the rear deck lid. Exterior door handles were color matched as well as the mirrors. I need those in PB3 light blue decals if anybody has them.
As well the Power seat mechanisms were redesigned in 77...I swear they weigh half that of the older ones and they worked better. There were lots of other weight savings...progressively fewer reinforcement brackets, regulators held in by aluminum rivets rather than bolts. etc.
Those decals were used through 1989 on the M body 5th Avenues ...alternate source for searches.
Another weight saving measure on my NY'er is that I have an 8.25 axle instead of the 9.25. I also have the Load Leveling Suspension.
Load levelling debuted on the Imperial in 75 and was one of the Imperial things carried on after the badge re-engineering, unkie the rear discs.
Are you sure its an 8.25? is your NYB one of the small block cars? Only C bodies that I've ever seen with the smaller diffs were the small block cars....rare in an NYB.
I remember I called your bluff on this a while ago and sure enough your pics showed it as an 8 1/4...I'm positive I have a 8.25. I have a 400 BB. I'm pretty sure that the majority, if not all the 1978 NY'ers with 400's have a 8.25 axle.