[AJSTANG]

Our engine combos produce about the same power. The heads are the same, the specs on our cams are about the same and the intakes are close in performance.

I recently switched from 3.08s to 4.10s. The mph stayed the same but I lost a tenth; probably due to the extra wheel spin through the first 2 gears.

I think your numbers will improve once you get an after market tach. The factory tach is way "off" in the upper rpms (over 5000). As an example, 5500 rpms on my autometer is equivalent to 6200 rpms on the factory tach. I shift at 5700 on the autometer tach and the factory tach needle is buried in the red and I still don't trip the limiter. So probably still short shifting with the factory tach. Good luck!