New rider here with Questions

Im restoring a 2001 VT600 I neglected for a bit. I bought the Bike used in 2013. Ran her for a bit with need of maintenance. Parked her for the off season and life happened and hadn't had time to get her fixed up. Recently started restoring her back to ride-able status. I'm mechanically inclined, but have never worked on a motorcycle before. NEVER dealt with a carburetor, so bare with me here. I've managed to scour this forum and get most of the details I need to get started working on it. I bought the Bike with minor mods, K&N filter with stock air box and cobra exhaust. I haven't been able to trace what model Cobras are on it. When I got to the carb, I was under the impression with the mods, they would have jetted the carb. The plug for the Air/Fuel mix screw is still intact. Everything I've read said that plug is drilled out and left out when rejetted for adjustments. When the bike was running, it didn't seem either rich or lean. So I guess my question would be, do you have to rejett with these mods or no? I plan on getting Velocity stacks or something high performance and know I will need to rejett, but until then, should I be concerned?