ok im new to having a mustang and probably considered a noob with this but i had a couple of questions. 1st off will an exhaust from an 87 and up mustang fit on an 84 since i want to put slp exhaust on it instead of my flowmasters. second off the mods i have on it at this moment are holley 4 barrel carb, edelbrock intake manifold,hooker headers, o/r H pipe no cats and flowmaster super 44s, MSD Ignition, what kind of hp gain we talking. and last question i have 289 high-PO heads and would that fit on the 302 block and would everything bolt up. sorry for the noob questions since i dont know all that much about carbed engines. thank you