I have a 53 3100 also, I used an 85 camaro drum brake rearend, its 62 inches and you can get the spring sadles from buffalo enterprises for like $135, the tube is 2 5/8 and he also gives you the ubolts for a perfect fit. The rears are pretty plentiful and come in 3:23 and 3:42 ratios which are decent for highway driving, lokar sells an e brake cable kit so you can hook up the e brake,, hope this helps
