One of my next steps is to replace the rearend in my 76 regal to something with a little more grunt. I currently have a open 2:56 in the car. My question. Should I attempt to put in the new ring/pinion and carrier or should i take it to a shop and have them do it? Also, should i buy the parts or have the shop buy them? My next question, is a 3.55 decent or should i use a 3.73 For those that look, I also have a 2.56 posi unit (the whole axle actually) if anyone would like to buy it. It is out of a 76 regal. It is stamped 6 CH B, the CH standing for 2.56 ltd slip.
Your cheapest and quickest solution would be to buy a spacer plate for your 2 series posi rear and get some new gears or used gears. If this is strictly a street/city car, I would suggest 3.42. For highway cruising with a TH350 or TH400 stick with 3.08 for best all around performance. If you have an OD trans, you can go with 3.73 for all around use. If you have any local u-pull-it yards, check out the 80-87 Suburbans for 3.42-3.73 gear sets. If you have not done a gear set-up before and have the special tools, take the rear to a pro and have it done. Should cost about $200-250 for labor. I would have them replace all bearings, seals, etc while you have it apart.
