Ford used a 0.187 dia bullet connector. The other "standard" size is 0.156 dia. They are not interchangeable. There are several types that accept different size wires, usually the red insulator is for 20-20AWG, blue is for 16-18AWG, yellow is for 12-14AWG. The blue insulator size, 16-18AWG, is probably the most useful size. I got mine on e-bay.
The crimping tool may be found on Harbor Freight. DO NOT USE VICE GRIPS, it may not work and it looks "tacky".
Jim