The 348675 casting is one of many used for 250 engines w/o the integral intake according to the Chevy Inline Six Power Manual.
I don't know of a link, sorry.


1953 Chevy 5-window 3100
In the Stovebolt Gallery
More pix on Picturetrail

Dave
Engine & Driveline Moderator

If you can't make seventy by an easy road, don't go. ~~ Mark Twain