Foam & broken nuts?

[62beater]

today i started welding patch panels(in odd places, i.e. 8 in up from the bottom of the door...?) in my '62 4 door when i came about a piece of foam rubber in the bottom of the "b" pillar, this piece of foam had to have been place there some 44 years ago by a studebaker employee before the cap was spot welded on the pillar. Now, was it placed there for a reason (to stop noise/drafts etc.) or did this employee just happen to have this foam(read as trash) and cunningly dispose of it inside my pillar? Also I ovehauled the ohv 6 (last week) and i would like to note that every single rod nut was cracked from the threads radialy to the outside of the nut on the side of the nut that was against the cap. I didn't notice until after i installed #'s 1,6 & 5 but when i went to install rod and piston # 2 the socket wouldn't fit the one nut so i flipped it over and it fit, so i examed all the nuts to find that they all were broken. All the parts stores in the area acted like i was crazy when i told them i needed 11/32 sae conrod nuts, thankfuly pittsburgh crank could get them( not sure if mine are,but arp does list them) they are the same as the small journal chevy v8's i.e. 265,283,327