There isn't a specific dBFS level as to where your kick (or 808 bass drum) should peak but you can follow an arbitrary starting point of either between -3 dBFS, -6 dBFS, -9 dBFS, or -12 dBFS if you want. I would highly recommend you start at -12 dBFS because if you build your mix around the kick drum the final printed version will most likely max at -6 dBFS without the need to use a gain plug-in on the master channel. Always trust your ears though.
Technically that'll give you ample headroom for your audio tracks without hard clipping (or distortion) assuming you don't export (or render) your music project in the red (i.e. above a digital reference level of 0 dBFS). So mixing in the red isn't much of a big deal but perhaps you may want to avoid overdoing that, just saying.
What happens when your kick exceeds 0 dBFS
Most modern-day digital audio workstations (or DAWs) work in a single-precision i.e., 32-bit floating point with huge amounts of headroom. Some DAWs can do their thang internally in a double-precision i.,e., 64-bit floating point.Technically that'll give you ample headroom for your audio tracks without hard clipping (or distortion) assuming you don't export (or render) your music project in the red (i.e. above a digital reference level of 0 dBFS). So mixing in the red isn't much of a big deal but perhaps you may want to avoid overdoing that, just saying.
