For anyone that cares, I installed a 52123220AB in my 2006 Mega Cab automatic 4x4 with an 8" lift and a 3/4" thick TC index ring today. I'm waiting on a new output shaft seal, but it looks like at full extension, sitting on my lift with the wheels off the ground, I have 4"-4.25" of engagement of the drive shaft on the output shaft, should have more when sitting on the ground...

 

488 dollars and instock at lithia dodge,eugene,oregon.runs like a champ

 

wanted to give one last update since i started this thread forever ago.....

i am selling the truck with 260k miles on it and the same driveline i installed back in 08, one or two sets of ujoints later. many loads well over 22k and up to 27,500lbs

shees been a great truck and i regret having to sell her but i was passed down a deleted 08 6.7 from my company and i get to keep all the proceeds of the sale.

OH and you can have a driveline shop fab you up a steel one for 350-450 dollars that works just as well as the factory aluminum ones. my new 08 has a replaced steel one due to an accident.