MCE now has axle shafts and gears by the new-ish company Nitro Axle and Gear. We have been testing/abusing their 4340 axles since early 2010, and have had ZERO issues! The quality of Nitro products has proven to be extremely high.
To get these going, we have discounted the price as well as offering free shipping in the US
Check out our 'page and see a few photos and a short video of the Nitro axles in use:
Axle and Gear | Modern Classic Enterprises
We'll be updating the website and hopefully by the end of this week we'll have the full line on there.
Let me know what you need!