No, the aluminum 225 was discontinued because aluminum was much more costly than iron and despite the much faster machining and longer tool life, Chrysler were unable to achieve the day-in, day-out zero-problem production that they could attain with the iron engine. Given that nobody cared about a lighter-weight engine in the days of 29ยข/gallon gasoline, the decision to go to all-iron was an easy one for Chrysler to make (though one wonders if they ever amortised the fancy die-casting equipment brought in specially to make these engines).
