If I was going to cross breed some engines, I would opt for a full blown racing spec KR cylinder head (port polished ect.), uprated cams and a re-built bottom end. Would an ABF bottom end work with a KR cylinder head?
Also, what about a gearbox. I got a 5 (currently 4) speed box on the car, would that handle 160+ BHP and more tourque?
Kr head will work with ABF bottom end, however sure danny_p or rubjonny will shed more light on it than I can. there is a good build thread on here somewhere. G/box wise I'd say you'd need to make sure the bell housing matches up input shafts etc. But don't know how long it'll last.