do NOT put race gas is your stock srt-4,your asking for problems...i ran a 13.8 100% stock,with a spare,3/4 tank of gas...being able to drive the car is 85% of its issue being fast...ive seen MANY BPU upgrading srt-4's still in the 14's,while similiar setups would net high 12's-low 13's....if you cant nail your 60' ft and somewhat maintain traction it wont never see the "stock" 13.8 your looking for

My mods--3 inch downpipe,wga @ 18lbs,homemade intake...
1/4 times(ran at 13-14lbs)
2.0 60 ft'
13.8@104mph...thats on less/equal to stock boost levels