There are members who have a two series rear gear that would love to have a three series carrier. If you can find one iclose to you, you could swap rear ends. That way there would be no cutting and rewelding of the brackets and it would be simply a matter of bolting it in.
Or you could buy one from a salvage yard because they are simply scrap metal to them; because to my knowledge you are the only person on the planet that wants one. (I mention this because if there is no demand the price should be lower) If they want to sell you a 12 bolt rear for the same price as this unloved 10 bolt you know that they think you are not aware of the difference in value, and you might want to pointy it out to them by offering the current scarp metal rate for a 300 pound part. You want to locate one locally because shipping it across country would cost more than the rear end would cost.
There are not many passenger car tires thirty inches tall, so you are going to get a six or eight ply truck or worse a trailer tire (limited in top speed because the plies in the tire heat up as speed increases that cause it to blow out if driven too fast. Truck and trailer tires are also as hard as rocks to improve tire wear, which reduces traction.
Second thing wrong with your plan is that air shocks will TEMPORARILY raise the back of the car up. BUT the shock mount was not intended to be stressed by holding up the car. On a Camaro or Nova it would punch a hole through the trunk (they don't have a frame to mount the upper shock to). You have a screw in stud top and bottom, but they are not designed to support the weight of the car. Additionally an air shock picks up the weight of the car by placing compressed air in the bladder around the stock shock. Just as would happen if you put a hundred pounds of air in your tires it would ride as stiff as a lumber wagon.
I highlighted the word temporarily because the air shock was not intended to raise the car's height. That was a marketing man's idea on how to improve sales at Gabriel by taking a part designed to assist a pick-up or station wagon dealing with a extra heavy load (such as the soccer team piling into the back of mom's wagon, or your bringing home a load of dirt for a gardening project with your pick up. Back in the sixties jacking the rear of the car up was all the automotive fashion, just like low riders are the fashion statement today (this too will pass).
The vehicle wasn't designed to carry this extra weight all the time, so the air shock was a temporary crutch to get you past this momentary extra load requirement. This is the difference between engineering and marketing. Ad men lie, and engineers tell you "I canna do it Cap'in, I canna break the laws of physics!"
Last edited by Big Dave; 10-21-2017 at 01:21 PM.