They work on some stuff and hurt power on other stuff. Way too many variables to say it always helps or always hurts. But one thing is for sure they ALWAYS look bad ***. Are you not going to dyno this engine? That’s the only way to know.
It will get dyno tested but I think it’ll stay no matter what. The engine is going in my dart and it’s only track legal to 10.0 in the 1/4 and it’s already faster than that with my 470” build.