i just put a new rpm intake on my 428.i forgot to bend the head gasket tabs down,and got a bad seal,and it smoked.ok heres where i got lucky,when i took the intake back off,i found a piece of alu. in the lifter area.it is round and has a drill bit mark on one side and rough cast on the other.it matched up with the intake bolt holes.it somehow got in the intake at the edb foundry and i didnt find it when i checked it over before i put it on.i had it upside down a few times but it didnt fall out till i ran the engine.im lucky i found it before it wound up in the wrong place.theres no damage on my intake,it was where the bit was about to pop out the back side,a little chunk came off before the bit popped through.check your parts out good before you put them on,i might not be as lucky next time