tjeter

My friend has a 1987 RX-7 Turbo II in mint condition and hes selling it to me i already put the down payment on it actually. He's added some mods Racing Beat cat back and FCD. The car drives perfectly fine but to get it to idle right u have to drive it a bit or give it gas for alil while before moving to get it to idle perfectly. My friend is 100% sure its the fuel pressure regulator because the car is running rich and he says it will bring downt he psi and get everything running fine my question is will an aftermarket fuel pressure regulator from rx7store.com fit on the stock fuel rail? can anyone help me out please thank you im new so hoepfully you guys can help me out.