Looking for an engine oil dipstick tube

[JMD]

Hi all,
I'm looking for the stock dipstick tube for the 454 I'm swapping into my k10. The casting number on the block is 14015445, which according to various websites means it was used in '78-'88ish light duty trucks. I'm having trouble locating this part anywhere on the internet. I'd rather not use one of those gaudy chrome universal tubes, and the junk yards are picked clean when it comes to big blocks. What are my options? I've included a pic of the engine for a reference, can anyone tell me what size oil pan that is? Thanks.