Are my rpms too high? Speed to rpm chart?

[bob_98sr5]

Are my rpms too high? Speed to rpm chart?

Hi folks,

I had a 2nd replacement differential put in by Enrique. this one seems to be smoother than the first one he put in. the other one had a lot of noise from being worn out. this one makes less noise, but it still appears to be louder than my original that went out. That said, my rpms seem higher than I remember w/ my original differential. I can't quantify the original, but here's the rpms at 60 and 70 mph of the current diff:

60mph = 2500-2600

70mph = 2700-2800

Is this about right for a 87 300D? Is there a reference chart that anyone knows of?

It just seems a little noiser and higher than i remember. it too could be the $50 tires that I put on a few weeks ago. Or (gasp), could it be the transmission?