Also, have a clear picture of what you want the finished project to look like and what it is you want it to be (go fast, all original, street rod or whatever). Figure out what your anticipated casts are and leave extra cash for the unforeseen pieces that always crop up on any build.
I am starting work on a project that has a parts cost of excess of 100K. After all is said and done I build an extra 20% for whatever. This way you can manage your project and as seen to many times when people go over budget, the project gets neglected, the person building loses interest and somebody picks up a project at 10 cents on the dollar.