Yukon XL 4X4 lift need transmission upgrade info

[thegeneral]

Just dropped my Yukon off to have a 6" lift and 35" tires put on it. It was stock to begin with.

I am going to change the gears in the future from 3.73's to 4.56's but my question is-

I would like to change out the existing transmission to something much more heavy duty, to accomodate an engine swap I plan on doing in the future.

Is there anything out there that would be a step up from what came from the factory? It is a truck with 200,000 miles on it, and I like to be ahead of the game. I plan on keeping it for a very long time.

I have the 4L60e transmission as of now.

My plan is to put a bigger GM engine in it in the next 6 months.

 

[WildBill]

I know you can build a 4L60E pretty stout for not too much $$. 4L65E is a bit stronger but I dont know the details of the swap. 4L80E is the big step up, but its a longer unit and requires a custom crossmember, shorter driveshaft, and different differential gears. 4L80E is sweet but big $$

When my time comes, ill go beefed up 4L60E