Let's consider a stock EVO with 276 cranck HP vs an EVO with 360 cranck hp maybe 300/310 whp.
What Could I expect about performance improvement?

Stock EVO: 0-60=5.1 / 0-400m= 13.5-102mph

Modified EVO: ? ? ?

 

Well my car with the Vishnu Stage 1+ with 272/272 and test pipe has run a 12.5 at 109 at Bradenton Speedway. I think I may have just a little bit more power than 360 at the crank . I think that you should be able to run a 4.0 - 4.1 0-60 and a 12.6-12.8 in the qtr. Hope this helps.

 

probably something like this accordign to your model:

0-60 4.5-4.8
1/4 12.6-12.9 possible 12.5

 

Depending on your driving skills, with 300-320WHP, you should easily hit 12.5 to 12.7@106-110MPH, if your an excellent driver, you could hit 12.2 to 12.4@110 to 114MPH, then again if you suck at driving you may hit 12.9 to 13.3@104 to 108MPH. But I believe the average EVO driver, would hit 12.5 to 12.7@106 to 110MPH.