Before I did my 80 swap I researched before and after track times and I couldn't find decent back to back slips. I was totally expecting to lose 2 tenths but figured the reliability and cost was worth it. My setup stayed the same only changing transmissions the 60 was stock other than servo including stock converter the 80 is 100% stock including converter. The only thing difference between runs was weather it was cooler but humidity was a touch higher. I wish the temps would have been closer but this is still the closest back to back comparisons Ive seen.

 

Mine ran faster with the 80e

 

My brother, JAKE99, lost .3 seconds but no MPH when he swapped. He had a H/C/I LS1 in his 99 RCSB, Yank SS4000, 4.56 gears and 28" slicks. He ran a 12.2@108 with the 4L60e/SS4000, and ran a 12.9@104 with the 4L80e/SS4000. Density altitude was quite a bit different, but when DA corrected it was about .3 and 0 mph

 

Curious about what the DA and corrected ETs were for both passes.

 

Yeah if you can compare the corrected ET's and MPH it will help to see the actual difference. Although it must feel good to actually run faster with the 80e and have the slip to prove it regardless of weather conditions.

This is the closest comparison I have seen for times as well, although I think I remember NicD maybe doing a dyno comparison between the two.....