I'm doing a lsx 6.0 swap in my sc400 and using a th400 tranny and I can't find anyone who can make a custom driveshaft for a lexus cause they don't have the right equipment to balance driveshaft I was wondering if anyone on here knows of a shop that can do it for me

 

I find this hard to believe. There are several shops that should be able to do this for you. Just them the measurements.

 

If you're dong a custom job like that, you have to know all your exact dimensions like length, width, number of splines, and how much torque and hp you will be running and you will need your output and inputs ends.
Once that's done call the "driveshaft shop" or google them.
They'll send you a form to fill out and you go from there.
It's not cheap, but they can make you one out of whatever material you want to go with

 

^^^^ +1

Driveshaft Shop is excellent with their work.