i would have thought one of the main problems you would encounter is the actual height of the engine as they are quite tall, i dont know if the ka engine mount is similar to the mk4 escort one or not but the mk4 escort mount can be modified to fit and lower the engine by about 20mm clearing the bonnet on a mk4, as for a ka it may have to go lower still
they are a stonking engine tho and very underated (especially by people on here lol!)