Quote:
Originally Posted by Whiskeydan
Only W126 diffs up thru 85 will fit.
Also, keep in mind that a lower rpm doesn't mean better mpg. It may now require more thottle (fuel) to maintain the same hwy speed since the engine is now not near it's peak torque rpm curve. MPG may drop. 
BTW, I just happen to have a spare 2.88 and 2.47. |
Not likley in my experience. (sorry to disagree, Dan). In a diesel swapping in a taller diff has always worked well for me.
I am running a 307 diff in my 83 240 with euro 300d motor. With the four speed I got thirty highway regularly. I swapped in my five speed and now get 35 36 regularly running 70 to 75 mph.
I could pull a slightly taller gear...maybe a 288 but taking off is already a bit dicey with the 307 rear end.
(the 307 with the 18% od is about equal to the 247). You'll never get 37 running an automatic imho....unless you run about 50 mph).
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[SIGPIC] Diesel loving autocrossing grandpa Architect. 08 Dodge 3/4 ton with Cummins & six speed; I have had about 35 benzes. I have a 39 Studebaker Coupe Express pickup in which I have had installed a 617 turbo and a five speed manual.
[SIGPIC]
..I also have a 427 Cobra replica with an aluminum chassis.