Dana 60 vs 8 3/4 -Steve Magnante Hemi Dart

I think the video is cool - and pretty good info for some of us with cars at a power level that might start tweaking our 8 3/4 housings. I wonder if he had a second driveshaft already cut for the 8 3/4 - or did he just "wing it" and make his original driveshaft work with a length not optimized? I was under the impression that the shaft would be shorter when using the dana 60 - and maybe a little too short for the 8 3/4?
I think the video is cool - and pretty good info for some of us with cars at a power level that might start tweaking our 8 3/4 housings. I wonder if he had a second driveshaft already cut for the 8 3/4 - or did he just "wing it" and make his original driveshaft work with a length not optimized? I was under the impression that the shaft would be shorter when using the dana 60 - and maybe a little too short for the 8 3/4?
When we did our test we had two different drive shafts