Help on 408 build

I recently finished building a 408 stroker LA engine. Before I started I didn’t really unstand what I was doing in terms of what cam and what pistons. No idea on compression which was a huge mistake and i don’t think it was a properly thought out build. The car seems to be lacking power and no matter what I do and can’t get it to stop pinging under load. I was wondering what I could do without spending a ton of money on bringing the car in.

This is is the info I have on the build
-408 scat flat top stoker kit with forged pistons
-mopar m1 single plane intake
-lunati hydraulic roller cam and lifters(Advertised Duration 270/278, Lift .515/.530)
-j 202 heads ported
-holley 750 carb
-(no idea on compression) shouldn’t be higher than 11.1) I have tried octane booster with no luck

I apologize on my lack of knowledge, please feel free to rip on me. figured I’d ask someone with more knowledge on this stuff, thanks