I have a 390 in a 69 F100 my problem is that my dad had some engine work done to it and I am now in trouble cause he past away a year ago and nothing is stock. I was trying to go thru it and clean it all up since it has been sitting for about a year and a half and I "chunks" of metal in the oil pan. I am not sure of what it is so I was going to change the crank and the cam just to be on the safe side. when I removed the cam it looked alright just a couple of burnt spots but nothing major I havent got to the crank yet but my question is can I ( or is it even visable) to put a 427 crank and cam set in it since I do know that the cam is not a 390 cam. My next question is if I dothat will I still have my top end power or will I loose it?