Im wondering which manifold will perform better for my needs. Ive read that the performer x is good for midrange power untill around 3000-7500 and then it drops off and the ive heard the victor x is good for top end power. Ill be reving to about 8500 or so and im shooting to break 500whp which im more then sure ill be able too. Also should i go with ITR cams or keep my stock GSR cams? The head is built p72 and was ported by DFE Enterprises. I believe im gonna run the garret t3 60-1.