OP, you realize that unless you have a cam, raising the rev limiter is pointless as your car has stopped making power.
It's not a Honda, your car makes power early and then falls off by 5,500 rpm. By 6,000 rpm, you have already lost 30 rwhp and 70+ rwtq from peak with it falling off rather quickly. Raising the rev limiter to 6,500 or 7,000 rpm will just make your car slower as it will have ran out of breath.
99 Chevrolet Camaro Z28 M6 - 6.676 @ 103 in 1/8, 10.512 @ 130.2 on street tires, H/C/I
93 Eagle Talon TSI AWD 5spd - Built 6 Bolt, 16G Evo3, HKS 272 Cams - under construction
94 Mustang GT - 5.0 bored and stroked to 347, Vortech V1 @ 10 PSI, Tremec TKO 600 - PIA