I have a 91 that I installed an E303 cam, explorer upper & lower intake, and Hooker equal length shorty headers, H pipe, flowmasters. The engine has started to blow bubbles so I need to pull the heads. Are the GT40P heads worth buying? Will I have any fit issues or spark plug clearance with the shorty headers? I changed the head springs to Lazers when I installed the cam. Will I need to change the GT40P springs and will my Lazers work since they only have a few thousand miles?