Looking for ratio on rear end and other info concerning gearing vs. mph

[b-rett]

hello all,

i have just recently purchased an r32 GTS 5 bolt rear diff for a 1jz_240 project. i am running a 5-speed r154 trans from the 7m chassis (toyota) - if anyone is familiar with it.

first, i am wondering what kind of rpm vs. mph you all are seeing with your rear ends? i know the transmission gearing will differ a bit, but just trying to get a rough idea of what i can expect.

second, i'm seeing a few threads where ppl are stating that the gear ratio on the 300zx turbo diffs (3.69) is a higher gear ratio than say the non turbo diffs (4.10). what is the logic behind the numbers nissan has published/what exactly do they mean?

for instance with the 3.69 gearing, are we at 2500rpm going 70mph? and with the 4.10 are we at 3500rpm going 70mph? this information would be helpful. thanks a million!