I take it you mean the complete differential. Yes it will bolt in. I used a ‘78 diff in my ‘70 years ago. Pinion bearing went out. Not sure about the E brake cables mine were not hooked up. I don’t remember what driveshaft you’re using in your set up, I was using a stock 620 driveshaft with my l20b 5-speed, and of course it bolted up with no problem to the ‘78. Of course the one thing that is different is the wheel stud size is bigger on the later trucks than the ‘70. It worked out OK for me because I was running ‘73 front hubs anyway. That 620 rear end is a little wider as well.