1477857 is the casting number for a 63 390 block, so you definitely have the right engine. The 64 429 is basically the same engine with slightly larger bore/stroke. External accessories are the same. I used a Carter M3993 pump on my 429, and it fit and works perfectly, no problems. I got it from Rockauto, cheaper than Amazon and faster shipping. [url]https://www.rockauto.com/en/moreinfo.php?pk=295939&cc=1320343&a...[/url]
They must have really reduced the price recently, because i paid them about $81 for mine back in March. It's $31 and change now.
It's the same size, and looks exactly like the AC pump that was on there -- possibly the original to the car.