I've been driving my car with its current mods for more than a year always seeing n passing cops everyday where i live and other cities by here except for that one town Union which i hardly pass through only to go to the highway. But everday n almost everyminute i pass police cops here n other cities right by here riding over 3.8 rpm nearly 4 or about 4 rpm... they got no problem with it never had any problem with it.
But i mean i the police here knows the car is street legal n some police cops here tell me it "sounds great n must be very fast, would love to try and race that." As long as its street use n street legal engine mods then there shouldnt be any problem or concern of trouble.