I am pulling the heads from my 75 460 to have them ported and rebuilt. I use the truck for hauling, not racing or show, but I do like the idea of having some power under the hood. If I were to change out the cam to a mild performance grind (not sure what as I have not yet looked into them), would there be a noticeable gain in hp or torque? And, if I did go to a modified cam, would I need to have the valve springs replaced when the heads are being done?

 

there would definitely be a HP and TQ increase. when rebuilding the heads they should check the spring pressure and more than likely they need replaced anyway. Then you can put in some springs that can handle the cam you decide upon.