Best engine for KE is 4AGE from AE86 halfcut.
When you buy AE86 half cut, you get everything to complete the conversion (engine, 86 engine crossmember, 86 steering rack, t50 g/b, suspension, propeller shaft, LSD, etc)
No need to modfiy, everything is plug and play.
No need to headache to look for this and that.
NO need to worry JPJ or puspakom inspection.
If you put other engine, you have to look for this and that, at the end will cost more money and time. TRUST ME, I've seen it and the owner really
Also, in future if you want more power, you can just upgrade to AE101 or 11 or because you have all the parts when you converted 86 engine earlier.
Good luck and hope your project will be successful