I have been told conflicting stories by so many people. which are the real gears 3.42 or 3.43. If they bothe exist, which one was put in camaros, I heard mostly z28's?

 

3:42 and 3:43 are both real ratios, neither is a real gear, more like a pair of gears working together. either ratio might be found in a camaro. what do you mean " you heard mostly z28s" mostly z28s are camaros with gear ratios. what's your real question?

 

The division leaves you with a number that is most accurately rounded to 3.42. No F-bodies received a 3.43 ratio.

 

I always thought that 3.42 was the gear and that is what everyone told me, but when I actually talked to a friend who has owned and worked on a lot of camaros and mentioned the gear, he said 3.42 was never put in camaros and it might even mess things up, that is why I wanted to clarify. He said it was always 3.43. thanks for the info, but people are actually convincing me to go with 3.73's instead. thanks again!

 

Rear end ratios aren't that hard to figure out. They're the number of teeth on the ring, divided by the number of teeth on the pinion.

They therefore are ALWAYS the ratio of 2 whole numbers; since no pinion or ring gear (at least, no functional one) can have a fractional number of teeth.

The number of teeth on the pinion is nearly always somewhere between 9 and 15; the number of teeth on the ring is nearly always somewhere between 37 and 45. At least one of the numbers is nearly always a prime number; that makes the "preferred" pinion tooth counts 11 and 13, and the "preferred" ring tooth counts 37, 41, and 43. The reason they prefer a prime number, is because that way all ring teeth mesh with all pinion teeth over the longest possible number of revolutions; they wear more evenly, and run quieter, than any other combinations. The best ones are combos of 2 prime numbers. The higher the ratio, the more critical that becomes. You can get away with non-primes more easily in the lower-numbered gear sets.

So for example, 3.08 is 13 & 40 (in the 7½", or 12 & 37 in some other models); 3.73 is 11 & 41 (a very good combo); 3.23 is 13 & 42; 3.36 (another very good combo, not avail in the 7½" AFAIK, but common in 12-bolts) is 11 & 37; 3.42 is 11 and 42; 3.27 (9-bolt) is 11 & 36; 4.11 is 9 & 37; 2.73 is 15 & 41; 3.23 is 12 & 41; etc. etc. etc. Always whole numbers, almost always at least one is prime, sometimes both.

It's not hard to see that there are only certain possible ratios, based on integers within the range that produces gear teeth sizes and numbers that work well for mass production and durability and cost.

 

I recommend 3.73 gears. I went from 3.23 to 3.37 and it made a huge difference.
Easier to accelerate off the line as well as from a roll at any speed. In fact, it lowered my ET by half a second and I gained 3mph.