A starting point

Quick and easy way to tell if it's a 225,look at the waterpump bypass hose,if it's around 3 inches long it's a 225.If shorter around 1 1/2 inches it will be a 170. My 63 has a 170 auto and came with 3.23 gears. I swapped the rear for 2.76 to handle the freeways here in Vegas. Good for the low 20's in MPG. That thing looks great for a 50 year old car.
Get all the parts you can even if you never put them back on the car. For me the main selling point is if the car is complete, that way I don't have to pay big bucks for things like trim.Enjoy it !!