you cant but i can the mods done to dons car ( or gavs old car for those that no him ) were done with drive ability , trq and reliability in mind. bar the final drive mod, which tbh i dont think its worth doing unless your having the box out for some other reason, then its as far as you can go. yes you can fit a shrick , but for the cost , youd be better off going charged , be that super or turbo.