LeeSpeed 84 pitch (84P) pinion/spur gears were released last year, but this is the first time they've been available large enough for oval racers. 84 pitch gears provide 2 slight advantages over 64P gears:

1. They are a little more efficient due to the decreased angle of attack on the teeth. You can feel the difference when comparing rolling 84P gears together versus 64P gears.  The 84P gears are much smoother.
2. Secondly, when you make a single tooth pinion change, it's a smaller rollout change. This let's you fine tune the rollout a little better.

These are surprisingly less prone to stripping than you'd think because there are 2-3 teeth touching at all times. At IIC in Las Vegas this year, even some 1/12th open mod cars were using them, so they can handle the powerful motors.

148T (approximately 112T 64P equivalent)
150T (approximately 114T 64P equivalent)
152T (approximately 115T 64P equivalent)
154T (approximately 117T 64P equivalent)

Tip: To find the equivalent 84 pitch gear to a known 64 pitch gear:
There are approximately 32% more teeth on 84 pitch. So a quick and easy way is to multiply your 64P gear times 1.32.

Example, if you have a 112T 64P spur, and you want the 84P equivalent.
112 x 1.32 = 148

Sold as a single spur gear.