I've got a 1986 IROC. Already swapped the 9-bolt differential out and put in a 10-bolt in from a 2002 Camaro SS. The 9-bolt had a gear ratio of 2.73. The original 10-bolt gears are 3.23 Auburn limited slip. The car accelerates nice, I definitely noticed the difference from 2.73 to 3.23 gears. I'm ready to send off the current Auburn limited slip unit to the recycling bin and purchase the Eaton TrueTrac carrier. Also, while I'm in there I've decided to go another step higher in the ring and pinion gear ratio to 3.73...

Anyway, I decided to start this thread because I need feedback on which brand of ring and pinion 3.73 gearset is the best brand. I plan on eventually pushing just over 500HP from a custom 377/383 stroker... Summitracing has:

1) Summitracing
2) Richmond Gear
3) Motive Gear
4) Yukon Gear and Axle
5) Allstar Performance
6) USA Standard Gear

 

I pick whatever I can get my hands on. My race car has some used NASCAR gears in it. They were polished and back cut. Picked them up off Ebay many years ago and never had an issue with them. I can't even remember what brand they were. Probably Richmond but might be US Gear.

Mine aren't even a racing gear. Racing gears are made from harder metal and can become brittle and crack. Street gears are made from softer metal and will flex when stressed.

I went through many different gear ratios over the years as power level and tire sizes changed. Different ratios had different brands. I've finally settled down on 4.86 gears.

Buy what you can afford. I highly doubt you would notice a difference between any of the brands. If racing, buy a brand that provides contingency money.

I wouldn't be too concerned about brands when putting parts into a 10 bolt. It will break eventually no matter what brand of gear is installed.

 

With 500 HP it probably doesn't matter what brand you use, you will probably break it. Motive is pretty good, and Yukon. Summit, Allstar and USA Standard are cheap gears that will probably sing to you while you drive. US Gear is another good one from Tom's Differentials, which is also a good place to get Eaton products.

 

I usually use Dana/Spicer, US Gear (not sure about USA Standard Gear, sounds like a chinesium substitute trying to confuse the inattentive, but what do I know), Superior, or Precision. I might use the Yukon, or the Motive (AA&M... the GM source). Would ABSOLUTELY NOT EVER UNDER ANY CIRCUMSTANCES WHATSOEVER use the Richmond unless it was a TOTALLY DEDICATED trailered strip car that NEVER hit the street, not even for a cruise to the drive-in on a pretty Sat afternoon, in which case I might not use anything else. I might use the Summit set if I could figure out where it actually came from (since as we all know, Summit doesn't own a gear factory); I'd sure NOT use it if it came from India, China, Thailand, etc.

I'd put what's appropriate to the use the car gets NOW in it, and worry about "eventually" ... eventually. Which sounds like, it's a 305/auto car, so the Yukon or the Motive would be fine.