Whats the biggest wheel you can fit on a stock floored 67-72 F100s??

Was wondering what was the biggest wheel you can run on these trucks? was thinking of 24s but im unsure?? if a 24 can fit what all has to take place upfront?? any info will help out

my 2 trucks are of the 73-79 body style but i am pretty sure they are very closely similar... my bronco is setup to lay on 24s i have a full frame with a 73-87 chevy front crossmember with suspension on it- it's pretty much setup like a z'd front with chevy stuff