GT lower air dam

I am currently working on taking this car from 214mph to 230 without changing much on the engine. I am considering a GT/pace car lower air dam that I will modify a bit (within the rules.) It doesn't have any power adders (not allowed) and it weighs 4400 pounds without me in it. If that doesn't work I will put my big old air dam back on. The car has run 204 in the mile. (at a lighter weight,) The current 351C, single 4 bbl, 4 speed top loader, GV overdrive and 3.73 8.8 will not be changing. I can't smooth out the front, It is running a production class so the 79' front parts have to stay un modified. So with that being said, if anyone has a Gt lower valance that is a bit beat up and their willing to part with it, shoot me a message! https://www.facebook.com/View: https://www.facebook.com/joe.jolly.106/videos/390367939138614

We add weight till the tires stop spinning. The car was spinning the tires and wouldn't accelerate anymore above 170 mph at 3120Lbs. Many high hp door cars and roadsters weigh 5 to 6000 lbs. Wings add downforce but they also add drag. I am production class (body) and cant really change much other than add the air dam. The roof rails are mandatory on everything that has a class record over 200 mph.