I need an 75-n series batter, for a 1994 Pontiac Formula Firebird (V8)?

75 is the group size of the battery meaning the dimensions of it. There are group 26, 65, 78 ect. Every group size number is the same regardless of the battery brand name. The letters in it change depending on the brand name IF, its after the -. If its before the dash it can idicate a few things. If its an F it means front facing terminals, if its an R it means reverse teminals, which means the + and - are backwards compaired to how it normaly would be on that batterys group size. The letters after the dash mean nothing in terms of the size. and example is the 75-N is the energizers part number, the duralast battery brand names part number is 75-DL. Pretty much all GM vehicles between 1988 to about 2005ish are pretty much all side post battery's. These group sizes are group 75, 78, and 79. with 79 being the biggest. What your car takes is a group 75 battery. All group 75's are side post battery's mainly for GM applications.

Now, Cold cranking amps means the amps the battery puts out at a temp of 32F or colder, regular cranking amps are what the battery is rated for at for above 32F.

If your looking for a decent battery i've always liked interstate and duralast battery's. Better warrantys and better quality. Genraly a battery with more CCA or cold cranking amps is better because your starter doesn't work as hard to turn the engine over so its less stress on it and less heat.

Genraly better batterys have more plates or electrodes in them which give them more cranking amps and they last longer as well.

Hope this helps!

Your batter[y] wont final more than two years within the desolate tract warmness no matter what it's. Go to AutoZone, buy their center grade battery and store the receipts. You can be again.