Hurst Drivelines used Inland as the supplier for my conversion. They exceeded all expectations. I had the driveline within 7 calendar days of submitting my measurements.
I run a 4" Carbon Fiber driveshaft from Mark Williams. Super light, less high rpm vibration and stronger than aluminum. One good advatange (hopefully it never happens) is that if it fails, then it will shatter rather than poke threw the floor. It's rated for drag launches and high driveline rpms.
I've had several done from Inland Empire. Always excellent quality, and always on time (about three days from ordering to delivery for me). The last couple were 4" aluminum, have done 3.5" also in the past.