Finally got the pan sorted out, didn't turn out as clean as I had hoped but it will work. I am still relatively inexperienced at TIG welding so it is a bit of a challenge but at least with TIG I know it is sealed.
I installed my rear main seal retainer in the block (hate those things), but while doing so I noticed a date and a name stamped into the left rear pan rail. I believe the date is when the short block was originally built and I am thinking the name is from someone who once owned the motor, most likely stamping it so that if it was at a machine shop they would be able to ID it.
I need a timing chain cover for this motor and I have what I thought was a 440 out of a motor home, well after tearing it apart I discovered that the motor is actually a 413 which they used up until 79 in motor homes (who knew..). The block would be a good donor for a stroker or something, I will hang onto it as garage art I guess (gives me a place to rest my unused 440 6 pack intake
Interesting thing with the 413, there are no numbers stamped on it anywhere to indicate displacement. The front pad has what looks like a number 1 and perhaps a 0 stamped onto it but far apart. There not any numbers on the pan rail (where the partial VIN would normally be). The casting date is there (7-10-72), so this had to have been in a 1973 model motor home.