So I found an odd situation around this. At the same time I did the same swap I needed to fit 28 inch slicks in my 73 Duster. I noticed they wanted to try and rub against the front of the wheel well but had a little extra space in the back. It seemed if I moved the axel back 1/2 inch that everything would be more even. So I had some half inch aluminum plate and I made two spacers to go between the frame and the front of the front rear leaf spring mount. I got some half inch longer than stock grade 8 bolts and put them through. This move the axel a half inch back to Center the wheels and consequently gave me the right length for my drive line. I can tell you getting one shortened is a lot cheaper than getting one to grow.
