Newbie 65 Dart suspension Question

All A-body rears are a bolt in,7 1/4,8 1/4,8 3/4 and a Dana.I have the 8 3/4 in my 66 Dart with 3.91 sure-grip with Moser axels 5x4.5 bbp.I have 2 1/2 x 10 inch brakes on rear.I also did the disc. brake swap up front.I dropped a 360 in the car useing Spitfire headers(cheapest $235).Hope this helps!