Falcoo95--Welcome to the forum.
Action has pretty much steered you right. 6 cyl cars were 4 lug and 9" drums. V8s got 5lugs and 10"drums,Car reviews of the period said that V8s got Fairlane suspension pieces and brakes.
Underbody did not change much 1960-1965 except for the parts that were strengthened or added. Convertibles have extra beef added in a a few places to try to replace the rigidity lost by removing the top. Even so convertibles are not known for their rigidity. Cowl shake is present in moderate amounts. A sedan or hartop will be more rigid.\
Sprint is a sub-variant of Futura. All Sprints are Futuras, but not all Futuras are Sprints. There might have been a few 1963 Sprint 6 cyl cars, but in general all later Sprints are V8--Windsor small block--mostly 260 with 2 bbl. 1965 added the 289. Anywhere a 260 is bolted in, a 302 fill fit.
Rust is the enemy. Ford learned a lot in the years between Falcon's introduction and Mustang----and Mustangs rust badly, too.
Here is an interesting tidbit for (new) Ford lovers--Ford has introduced 3 new models over the years that each set the record as the most sucessfull new car model introduction based on sales. First was the Model A. Second was the Falcon--it was the right car at the righ time-they sold MILLIONS of them. The third most sucessful new car was, of course, the Mustang ( largely based on a Falcon floor pan and running gear. Also when you consider the sicess of the Falcon, remember that it come right on the heels of the Edsel fiasco where FoMoCo .lost hundreds of Millions of dollars. Yet, HFII gave the go ahead and allowed the falcon to be born.
Some books that will help you---FALCON-the New-Sozed FORD, by Ray Miller first printing 1982 Library of Congress # 82-090194. This is largely a picture book covering 1960-1970 1/2 Model years but mostly 1960-1965. There is some history and some reprints of early ads, but mostly, Mr. Miller walks around each car with his camera and photgraphs EVERYTHING and shows the changes over the years. Not much on "How To" hot rod a Falcon, or what parts fit, but a good history of how Ford made them.
A Factory Shop manual is a must-have for the approriate year.
I am a great fan of the 2 volume Ford parts Manuals--Iluustrations and Text
"Most" of what works on early Mustangs, as far as brakes, axles, springs etc, also works on Falcons.
Good luck with your project--You are at the best part--looking and investigating costs almost nothing. A rust-free car from the SW is always a better starting point than a salt-region rusty wreck.
Where are you located?
There were 435, 676 Falcons produced in 1960 and 471, 191 in 1961 and 396, 129 in 1962---all these were 6 cylinders
In 1963 there were 265,518, but Ford did not record how many were 6 cyls and how many were 8s.
In 1964, the numbers are 130,103 of which18,108 were SPrints and had to be V8s, but Ford did not record how many others might have be V8s
In 1965 total production was 171, 442, but Sprint had become only a trim option at that point.
You are looking for a rare car! Good Luck ( You only need to find ONE.)