how strong is the 8 3/4 #741 case?

I ran my '68 'Cuda FB FS at the strip well over 350 times (at one point I had all the timing slips) and turned 13.50's @ 105. All on the original 8 3/4 with 3.55's. With 220,000 miles on it now, all is fine. Just change oil regularly and keep the u-joints lubed and tight.