Thanks for the replies everybody...... this is important info for me. Am inclined to run with retro-upgrade later model 114/115 box even though the boneyard has pair of 116's - somehow i just dont trust late '70s steerage box on account of probs I've read while searching this topic here.

I guess it's true what they say about steerage adjustments causing quick wear to gears..... Tightened the adjuster (counter clockwise) 1/4 turn last year and now with recent allignment and new front tires soft handling is isolated at steering box alone - although new Bilsteins would help.

The '79 240D has only 130k miles - but is driven hard on country roads at top speed, wailing around corners cowboy style. Itsa fun car to drive, constantly shifting grears - but am thinkin manual steerage box would improve its handling.

It might sound pitiful but this 123 is the newest car I've ever owned.... meanwhile am still thinkin kingpin Heckflossen 110's have superior handling characteristics with high speed traction feeling of riding on rails.

__________________
'80 300SD/ w116
'79 240D 4-spd
'71 750cc Guzzi

previously owned:

'83 240D 4-spd
'77 280SEL 4-spd
'74 280/8
'72 250/8
'65 220Sb 4-spd
'63 220Sb 4-spd
'63 190c 4-spd
'61 220Sb 4-spd
'60 190b 4-spd