Stephen 87 IROC

Unfortunately the tranny gearing can't really be taken into consideration when comparing "2 identical cars" because there is no real identical tranny gears. An A4 could be a 700R4 or a 200-4R. An A3 could be a TH350, TH400 or a metric 200. They all have different gear ratios. I use a 1.76 first gear powerglide myself. That's like launching in second gear with an M6 then shifting into fourth at mid track.

Playing with the diff gearing can help or hinder the performance of the tranny gears. The 3.06 first gear in the 700R4 works well getting the car off the line when it has highway gears but with a set of 4.10 or 4.56 gears it can easily overpower the tires from too much torque multiplication. On the other hand an automatic transmission with a higher first gear can use the deeper diff gears better.

The M6's first 4 gears are not much different in ratio than the old 4 speed trannies like the Muncie. There's always a fun factor when driving a manual on the street but unless you're using something like a Lenco, you won't see many manual transmissions in drag racing unless they're in Stock/SuperStock.