Well, i don't know much about the conversion from carb to efi, but not gonna be an easy job, you might have some work on the car's fuel system and electronics too. As I have heard you might have to replace the petrol tank and add an inline fuel pump and petrol return lines, filter etc. And maybe you might also need engine bay to ecu and some interior wire harnesses? So am guessing it might cost 150-300k including engine+gb or more if you're getting a front cut. Anyway it is much better if you can go for a vtec model straightaway. But then if you can find the parts and capable of doing it, why not