Happy New Year, gurus of Benzdom!
I know a 190D 5 speed won't work behind the 617 in my 79 300TD, at least not without major surgery on the bellhousings, input shafts, etc. I wonder, though, in my ongoing search for a way to get a 5 speed into her: would it be possible/feasible to swap in a 2.5 5 cyl. with 5 speed attached, from a 190D into my 300TD?

That would also require fabrication, although probably less than adapting the trans alone. Custom motor mount arms at least.

I would try & find a junk yard that had a 123 & a 190 & do some measuring.
Would the sump clear the crossmember?
width of motor mount locations
How far back are the motor mounts from the radiator
does the starter motor clear the steering box
is the back gearbox mount in the right place
tail shafts are easier to shorten than lengthen

Just a few things I would consider. Hope that helps

__________________
Grumpy Old Diesel Owners Club group

I no longer question authority, I annoy authority. More effect, less effort....

1967 230-6 auto parts car. rust bucket.
1980 300D now parts car 800k miles
1984 300D 500k miles
1987 250td 160k miles English import
2001 jeep turbo diesel 130k miles
1998 jeep tdi ~ followed me home. Needs a turbo.
1968 Ford F750 truck. 6-354 diesel conversion.
Other toys ~J.D.,Cat & GM ~ mainly earth moving

Someone on here just finished putting a 602 into a 123 T, didn't they? He used a later auto 'box, but I'm pretty sure I remember reading about the car recently.

SEARCH!

Jay.

__________________
On the road, currently:
'83 300D (German spec.) 168k mi. - - Wolfgang (tucked snugly away for the winter!)
'87 300D 375k mi. - finally went over to "The Dark Side"
'87 300TD 225k mi.
Cannondale 66cm CAAD5 w/Campy/Jamis Aurora
Hujsak Custom Fixie/Landshark Track Shark Custom/Ahearne Custom 29'er