Few questions with my new Tamiya 501x

[501x_NewUser]

Hey guys/girls,

I just got myself a Tamiya 501x. I have been racing 2wd (Associated B4) for a little over a year and wanted to add another class to my racing (4wd!), but have a few questions (I am fairly new to the remote control world also so my knowledge is minimal still).

I have a Tekin R1 with a 537 Motor installed in the 501x and was looking at your gear ratio chart stickied in this forum, and I was wondering what kind of ratio I would want to start with a tekin 537?

I have 2 stock 96 Spurs atm, but I may try and get a 87 Spur also. Would the gearing ratio be similar on both that I should use with a tekin 537?

What would be the main difference with the two Spurs also?

Thanks in advance