My 164 runs at between 3500 and 4500 on the highway.

I've redlined it in 4th. I can drive around town using

only 2nd and 4th and other people in the car don't

notice the lugging. I never ever have to downshift

from 4th to 3rd, even on steep hills. I find myself

in 4th even puttering around town. All this tells me

that this car could live with a much taller rear end.

Do automatic 164s have a taller rear end? If so,

how much different is it? 1974 and 1975 automatic

164s are almost common in salvage yards out here.

How hard would it be to swap the two? I figure it

would be easier to swap the whole rear end and to

replace bushings in the rear end while I'm at it,

than it would be to just open up the differential

and replace just the gears.

chris