Spikes are by thier nature NOT 5psi as you seem to think, why do you assume all chips have the same characteristics.
Spike chips are hard on the head gasket end of, if NOT accounted for in the gasket selected.
I assume you don't then know what adiabatic pressure is ?
Even std cossie with ZERO miles were blowing headgaskets, when on NVH.
tabetha