65 ohhhh barracuda

That sounds way too long. You have a standard car slip yoke type small block 727 and a 7 1/4 rear? That should measure in the mid-upper 40's in length. A 904 with a 7 1/4 is about 52", but, the 727 is several inches longer, so, it takes a shorter driveshaft. If you go to an 8 3/4 (highly recommended) it will be shorter still.... about 2" IIRC.