What are you using the car for? If you are just using it to cruise/go to shows than I really wouldn't worry about it, just extra money. I bought rack and pinion steering for my '75 vette, but that's because I want to do road course driving with it. For drag, a lot of guys I know don't have it and they get by fine with out it. But, if you want a better steering car and you want to get rid of that crappy dead spot, it would be a good investment. So, its all up to you.

What kit are you looking at?