[ryan34691]

I'm looking to put a 9 inch rear in my 1966 coupe and I found a person selling a 60.5 inch rear casing on craigslist. I know the axle is too long but it comes with a third member. The price is quite good but he does not know what the gearing is. Can the gearing easily be changed? he wants $175 for the while package and I know the third members alone can go for a lot more than that. Are all third members different, or universal fit? Oh and can the case easily be cut down to fit the 57.25 inches it needs to be to fit?

 

[t.mcginley.jr]

First, yes a 9 inch rear can be cut down to fit. A shop can cut out a section from either side and then weld them back together. The spring perches will probably need to be cut off and welded back in the right place to line up as well.

As for the gears, its around $150-200 for new ones and then the cost of paying someone to put them in as its not a "backyard project". You can see real quick what ratio it is by turning the yoke and counting how many times the drums rotate per 1 rotation of the yoke. For example, if you rotate the yoke (where the driveshaft connects) 3 times and the drums make one full rotation, the rear has 3.00:1 gears.

Besides that, you don't know what kind of condition the differential is in or what it even is. If you turn one drum and the other turns the opposite way, its an open differential. If it turns the same way then it has a limited slip differential (trak lok). Depending on the condition of this it may need to be rebuilt along with installing new gears.