Wow, a 3.92??? I don't know if they make any of those. That 3.46 must be from a manual model. The highest ratio from a 124 that I have heard of was a 3.27 off of the wagons (I could be wrong though)

Anyway, the automatic turbo w124 diesels came with 2.65 diffs, so going up to a 3.92 sounds kind of extreme to me. The only benefit I can think of that giving you is really quick acceleration off the line.

Why do you want to run it at higher rpms? There should be sufficient power the way you are running it now. Heck, some of us 124 and 126 guys lust for the 2.47 or super low 2.24 for better highway cruising.

However, I guess it really depends on what gear ratios your trans has, and what kind of engine you are running. Is it the om603? Are you manual or automatic? Something sounds weird about going 105 and only being at 3500 rpm with a 3.46, since the 2.65 maxes out around 125 or so.

Also, if you are in Chile, I suppose there could be a lot more parts available there than what we are used to here.

__________________
Dan
2005 E320 CDI - 246k
1987 300SDL TD05-16g, Herlevi pump, Elbe manifold, 2.47 LSD - 213k
Past: 1987 300D - 264k