NHRA letter designations

[dave73]

Anyone on here up on the NHRA letter designations from the 60s-70s? I'm talking about the designations like A/Gas, SS/A, etc. I'm wondering what my challenger with a big block would fall under. From what I've read, the first letter designation is determined by the weight of the car divided by the displacement of the engine.

My car is 3100 lbs / 512 ci = 6.05

From charts I've found, would fall under the A class. Thinking mine would be either A/Gas or SS/A. But wondering what designates it as Super Stock (SS)

[floorit426]

It depends on the level of modification. If you're running stock displacement, 9" tire, full interior, etc., then it would be in the "Stock" class. I would guess C Stock, but all of these vary, depending on the model year. Some guys have been known to turn their '70 cars into '71 cars, to gain a more favorable class designation. Super Stocks are more modified, using bigger tires, cams, intakes, etc. Again, I would guess it would be a SS/E. Now, with the increased cubic inches and such, your car would probably be a gasser. I'm not sure, but I think the letter designation is determined by e.t. It is more of an unlimited class, with more of a "run what ya brung", mindset. That seems like it would be much more fun, because class racing is pretty tight, with the rules.

[RUNCHARGER]

Gas classes are more modified and you could run say a Sunbeam engine in your Barracuda. The A class in Gas would be the fastest class so the car would have packed less pounds per cubic inch than a B class gasser would.
There was also MP or Modified Production and that is where your Cuda would end up if you modified more than what was allowed in SS class.
A/SA would be the fastest class of Stock class cars with an automatic. A/S would be the fastest class of Stock class cars with a Standard transmission.
Sometimes these classes changed year to year as engines HP got factored. If you won a lot and no one else in the class could come close with their X or Y brand cars NHRA might tack on 20HP to the factory HP claim and you would find yourself 1 class higher and not competitive anymore.
Honestly I think the most popular class for Mopars back in the day just had to be SS/DA, that was where the Hemi Cuda hardtop ended up and it seems like just about every Hemi Cuda was raced in this class.