Need some head, help

Personally, I couldn't even consider running the "small port" 318 heads on a 360, unless they were highly massaged 302 castings. Seriously.....you're running heads that are smaller than stock?! Good gawd, your car may be a cruiser, but do you have any plans on revving past 3500? LOL No, I say go "J"....no question.

Another thing to remember is.....you're going to have to change your intake manifold to one that is designed for the taller intake ports of the 340/360 head.