What are the differences between the 8 3/4 & the Dana 60?

Actually a Dana 60 is more efficient and takes less HP/torque to turn than an 8 3/4. That makes up for some of the weight difference. The more race mods you add, like spools, lightened ring gears and both using 35 spline axles, the less difference there is in weight (apples to apples). Many Stock class racers, mainly higher HP BB racers who need the extra strength, have found no difference in ET's.

As for efficiency, the differences aren't big, but are there. It's mainly in the pinion-to-ring gear relationship. The closer to center the pinion is, the more efficient it is. Chevy 12 bolt is the best, Ford 9" is the worst and has the additional drag of an extra bearing.

8 3/4" are pretty strong. The most common failure is the ring & pinion teeth. Next is the caps. Dead hooking develops the most stress and finds the weak link in the drivetrain. Billet steel yokes are a good idea for some applications. The more HP is used and the heavier the car is, the more one should worry. Naturally, the more you race each season the more strain gets put on everything.

I always liked the ease of swapping gears in an 8 3/4 when you have a spare center section. But if you figure out the correct ratio to start with, you won't have to worry about it for a very long time with a Dana 60. It's also easier to check on the condition of the gears because all you have to do is pull the cover.

I have a 360 wagon that should eventually run low 12's. I switched from an 8 3/4 to a Dana 60 for peace of mind because the car weighs 3,800 - 3,900+ lbs., depending on class. Unfortunately, I haven't got it sorted out yet and didn't have enough runs on it to make a comparison when I switched. But I wasn't concerned that there would be enough difference in it to slow me down. Plus, the weight is where it will do the most good!