They do shift way nicer than a nv5600 in my opinion

I might have to look into swappin one in the future.....

my buddy is looking to do this swap on a CR with an auto but has been told that the NV4500 is a better tranny i guess they say the syncros in it are better than the newer ones but opinions are like buttholes everybodys got one. I would go NV5600:rocking:

I know the G56 is not as strong as the NV5600 or NV4500, but its supposed to be a lot smoother shifting. I think it depends on how much power you're wanting to run.

shoulda mentioned that. that is the main point here whataya doin with it??

Yes, a cast iron tranny is always gonna be stronger. The G56 is strong, BUT, the case will twist under extreme torque & horsepower and cause the shafts to try and become a pretzel inside.

But, for a guy like me with 500hp and liking to tow, it's the cats meow... If your buddy wants to swap, then a 4500 may be a good bet. There's a sled puller around here running an 06, with a 6.7 block, and a 4500.