Well here's some of the 1/4 times for the 5.0s as you can see fair bit of difference.
Modified.
BPT.............. 10.70 @ 131mph. Auto GS. M/T 26 x 10 Slicks
RDP.............. 10.96 @ 127mph. Auto GS.
Autotech....... 11.10 @ 129mph. Auto GT.
KPM.............. 11.14 @ 127mph. Auto GS.
RACEGT......... 11.63 @ 118mph. Auto GS.
XFT.............. 11.70 @ ???mph. Auto GS.
Modified (privately owned).
anthGT335.....
[email protected]. Auto GT.MT ET2 265/40/18
Sutty............ 11.38 @ 122mph. Auto GT.
Cygnet.......... 11.54 @ 121.9mph. Manual GT-P.
Scottrod1...... 11.95 @ 116.23mph. Auto GT.
Timtams......... 11.99 @ 121mph. Manual GT.
Buttnekid....... 12.09 at 118.9mph. Auto GT-E.
XRT-HOWSEE..12.09 @ 119mph. Auto GS. Tune & Filter
xrglen........... 12.30 @ 118mph. Manual GS.
Rusty62.........12.39 @ 113.7 mph Auto GT-P (Only mod air filter)
Bloosted........ 12.60 @ 113mph. Auto GT.
Stock.
200sxs15....... 12.27 @ 115mph. Auto GT.
Scottrod1.......12.39 @ 113.97mph. Auto GT.
shonkymofo.....12.47 @ 113.37mph Auto GT
HP-0351.... ....12.48 @ 113.54mph. Auto GT.
Unr33l........... 12.72 @ 110mph. Auto GS.
RDP.............. 12.90 @ 109mph. Auto GS.
HP-0351........ 12.92 @ 113.99mph. Manual GT.
Rockape........ 13.40 @ 108mph. Manual GS.
Generally just over half a sec which is a fair bit when down in times like these, I think the effect is even worst when they're modded / more power in them. You can also see how the GTs have a better tune from factory than the GS's in the stock comparisons.
This list hasn't been updated in ages though. One guy in a manual GT is really trying to break into the 10s hard and just cant do it, he has like 450rwkw or something lol 11.1s I think best he has got.
This guy:
anthGT335.....
[email protected]. Auto GT.MT ET2 265/40/18
Only had a tune and slicks, CRAZY to get 11.3 with only that.