http://s1149.photobucket.com/user/j...ve%20silencer%20pad_zpsd8vmizfm.jpg.html

I just opened up the valve cover on my 51 GMC and found one of these. I've never seen one before, glad there was this string to find out what it was. I haven't gotten the engine running yet so I don't know if it worked but the valve lifters are all clean...