Hi all... There was a post about a clackety clack noise from someones car...and this was possibly diagnosed as either a lifter problem or exhaust noise. If this was on a 413, dont forget that the rocker shafts on those older engines were bolted down on a separate pedestal, not a cast in pedestal like on the later big blocks. I had one of those thru bolts that hold the pedestal down get a bit loose.....instant clackety clack noise you would have sworn a lifter collapsed if you had heard it. It may be worth pulling a valve cover and checking those bolts just in case! Take care Mikey 62 Crown Coupe