I have a 94 F150 with a 300. I have pulled the manifolds due to cracks and the infamous "clicking". I bought two new manifolds - both front and rear. I'm not sure whether I should use a gasket or not. I know Ford didn't use a gasket, but that doesn't mean it's the right thing to do. With two new manifolds, do you guys think I should put on a gasket or use graphite grease? Advice is greatly appreciated.

 

The factory has a bit different situation when assembling these things then we have when re-doing them. Don't know about the EFI but gasket sets for the carbed engines are full length and cover the intake and exhaust. The three times I removed manifolds from a carbed application I used a gasket (Fel-Pro) for the install even though the factory did not use them. If the EFI manifolds share mounting bolts/washers I would think that a full gasket set would be necessary.