siwtching to Eddy heads on a 360

Taking a quick peak, I'd say you are going to be raising the compression a bit. Assuming your J heads are 72ccs, the larger Edelbrock is 65cc. So you'll gain a little. Not sure what gasket you use, but if you have the thin MPs now, you'll be using the thicker Felpro, so you'll loose a little there. Otherwise, no big change. You will (more than likely) need better springs than what the Edelbrocks come with. Dont use lift as the spec..you need to get the right pressures. One thing that screams at me tho..You're not anywhere near where I'd think you should be right now. I would invest in a better intake for you usage, and some better headers if they make them..I know that chassis is a pain. You may want to try the M1 single plane, or my "best choice" would be the Edelbrock RPM Air gap. Your intake is killing the torque, and the headers are killing the top end IMO.