Not exactly.  In your other post you mention it has front coils, which means it's no newer than 78, and makes a big difference in what front springs you'll use.  Motorhome manufacturers at that time ran a year behind, often selling a 78 as a 79, an 83 as an 84.  I've seen em dating back to the early 70s, and dolphin is only one brand, this is why I asked what a pre dolphin is.