One of my friends is building a gasser-look hot rod, to be used mostly for nostalgia drags. He has a 283 block that he wants to put together for the motor. He'd like to convert it to a 4-bolt configuration and has found the 'center' main caps. He recently ran across someone who claims to have a small-journal 4-bolt rear main cap. He received this photo of it, but the guy who has it doesn't have a Chevrolet part number. He can only tell Bob that it has the number '368' stamped on it. Have any of you engine builders run across this unicorn? Thanks in advance for any help!