Its really about marketing, but here is some helpful info from my 59 chevy truck owner's manual.
The Thriftmaster was the bottom of the line 235 ci 6 cylinder.
The Jobmaster was the 261 ci 6 cylinder.
The Trademaster was a 160 hp 283 ci v8
The Taskmaster was a also a 283 ci at 160 hp v8 but could also be had in Super Taskmaster form of 175 hp.
The Workmaster was the 348 ci 230 hp v8.
And the Loadmaster was a 322 195 hp v8.
There was also the Workmaster Special at 184 hp (with Special at this time usually meaning special pricing).
And finally, there was an economy optional Thriftmaster at 110 hp.
There you go, clear as mud.
I had a camaro with 230 i6 and it was a turbo thrift, and I think the 327 was the turbo fire.
Most of the car manufactures had names for their engines.
I had a 64 Riviera with the dual carter afb carbed 425 'nailhead' (nickname because of the small valves) with brushed aluminum valve covers which was called the Super Wildcat. A regular Wildcat had only one carb.
Chrysler had the 413 ci V8 called the Golden Commando.
You get the idea. Those are the ones I can think of off hand.
