80 series axle is a great way to go just remember that it is a couple inches wider than a 60 series.
Just cut off all the brackets and weld on some spring perches :)
Yep as Johhny mentioned the tundra upgrade is about the best you can do, unless you want to swap out your front axle for a Dana 60 and run some 1 ton brakes with a hydroboost setup.
Before I did my cummins swap I upgraded to 4Runner Caipers and that was good enough with rear disc brakes.
The reason why is so you can monitor the temperature of the air going into the turbo.
Anything over 1200 degrees F and you have to worry about damage to the turbo, keeping your EGT over that temp for too long can actually start melting the casting.
Looking great man.
You might want to swap out that worm drive clamp on your silicone U for a t-band clamp especially when you start to crank that boost out.