Mild steel and cast iron still have different thermal properties. After a bunch of heat cycling, it's going to crack.
lilhatchbesmokinU Don't sell your 3g because some dude said you should. That's stupid. Don't sell your car because your dad says its dumb. (unless he paid for it or in some way will be contributing financially to this) this is your car, your build, your ride. You have to drive it, you have to work on it and make the decision yourself. Giving up when things get tough wont get you anywhere. If you like the car and you want to make something of it then save your money and make it happen. I have a bone stock 3g. I want to make it fast, good looking and I don't care how much it costs, because I'll drive it till it quits, then I'll drop another motor in it. I love the car. It's great. You never come out on top. The only way you do is if you buy something brand new, and put a ton of money in it, then drive it for 30 ish years and enjoy the hell out of it, and hopefully it takes like the NSX or Skyline and is stupid valuable. You don't make a build based on your pocket. It's based on what you want. It's based on what you like. You will never come out on top monetarely. But it is fun as hell to pass a car 2, 3, 5 times the cost of your car. Build what you want not what your dad wants, or what someone else tells you. Take the advice and make your own build. I'd rather have a 3g over a civic because of originality. If you'd rather have a civic then get a civic. You'll never make it up modding cars. You mod cars because you love it, not to make a profit.