I have a 67 fb that came with a 289 and now has a 351w in it. The front end needs new springs. I am getting ready to order new springs and am not sure whether to order for a 289 or 390, they list different springs. My guess is the 390 springs are stiffer. They do not list springs for a 351w for that year. I have 235/60/14 tires that are currrently rubbing. I want a smooth ride, nothing bouncy. Is the 351w heavier than the 289? Any suggestions? thx.. Mike