I have been debating as to which engine would be best for me to eventually put into a 240Z. I have read about the engine models from The Datsun Z Garage and I enjoy the section on the P79 head mods. First off, I have an engine from a 83ZX, so which head is in that? I know that the 83ZX turbo engines have the P-90a heads, but I am not sure of what my non-turbo has. Whatever the case, does the 83ZX engine have much potential, or is there a better L6 that would prove to be a better option? Thanks.