Not sure if this has been asked before but keeping it locost and under 1100cc which bike engine would you use and why?

I run a K2 GSXR 1000 in my race car and keep looking at other engine options but they all seem close to each other in spec?

e.g. would a honda be more reliable?

how reliable has the gsxr been?

Faultless but always in search of more!!!

I do not need to change it just interested in everyones comments and feedback.