I've done a lot of research on gear ratios and have talked to serious race car builders, the difference in aero between a 7 and a Fury with exactly the same engine, gearbox, diff and tyres is 10mph down the long straight at Snets
125 Vs 135
I have seen over 115 with a Pinto 2.1 135 ft/ibs my next engine is projected at over 155ft/ibs 170+ bhp and an 8000rpm red line

My 3rd gear gives 90+ and I get well over 60 in second, I'm happy with that
80 in 5th is still a bit of a drag 4000rpm and first still runs out to early
At sometimes will get the 2.7 first but I'll have to sell some stuff first