I’ve got a 67 mustang with a 289, 4 barrel carb, 5 speed with a. 9” rear end. I understand it’s not a high horsepower motor so the question is. Should I invest in a pro comp cam, new lifters and springs, timing chain, headers and new gears? I think I’m pushing around 210-225 horsepower currently. I’m told this may get me to closer to 300. Is it worth the investment or should I just do a motor swap? I’m not looking for high top end speed just a quick off the line set up to drive on the weekends.