Newbie needs help decoding!

I am looking for my first Valiant. I want to find a numbers matching car. One I am looking at is a 1964. The /6 has 2463230-8 as the block code on the left side with 1 15 64 to the right of that. The engine stamping on the right front block edge reads V 17 2 07
Every list I have seen says the block code is for a 1965 170 slant six. The other codes indicate that this is a 1964 engine. What gives?
The fender tag gives the SO date of Jan 20 of 1964 for the car.