I'll start with low gearing of course, probably 30ish mph at first, starting out with a 12 tooth pinion on a 50-60 tooth spur or so (Does that sound right?)

I can't figure out exactly what speed I'll be getting on the top speed estimator sinced I don't know the diff ratios of my GST 7.7 yet, but is it safe to start with 12 tooth pinion and 60ish spur atleast?