OK. Dunno if I can diagnose the whole thing, but here's a hint. There are two different oil pumps for early pressure-feed 235s. I've mentioned this before. I posted pix at the website below:
http://homepage.mac.com/grenley/PhotoAlbum3.html The pumps seem to interchange OK, except that the different pickup angles make the stock pickup not clear the crank. I decided, after *two* trys at a new pump, to keep the old one.
As noted, this is a K103 block, i.e. November 1953, or 54 production model. Chevy used to let raw castings 'age' for a number of months, so it may have gone into production in late '54 or even '55. I don't know for sure, but I suspect the OEM pump is original. The engine is on its first rebuild. 8-)
Kind Regards,
George
53 3600
