Narrowing an 8 1/4" rear end, how is it done?

Yeah, it definitely could use a set of A body spring plates! But I would check the perch to axle tube welds closely, for definite… On the subject of an 8-1/4, some people have taken them and narrowed them with 8-3/4 / Dana housing ends and ordered Dr. Diff Green bearing axles with 27 splines. It’s also possible to upgrade to later 29 sure grip and axles in the earlier case, too. An LPW cap stud and Girdle make for a nice upgrade on an 8-1/4, too. I do know that an 8-1/4 does absorb less power than an 8-3/4 does. Less housing flex, plus they’re a little more efficient than the late fifties hypoid drive angle.