Richard: sorry, it’s streetsource… i don’t know if it still exists as an active location but you can still read posts and view pics on it But I have to use google to search it.
Ok, to clarify I do have dropped spindles, so that pushes the rim vertically up closer to LCA… so take this with a grain of salt, but I’m pretty good at visualizing things.
so rear of 22” Alcoa rim at full lock to front of stock control lower control arm is 1.5” clearance horizontally, rear of LCA to rim has much more room. Probably closer to 3”.
if we assume that the extended arms are only making up about 3” of the offset lost by removal of the 1ton rotors “spacer” when changing to 3/4 ton Rotors. that would put my 22s, if I tried to run 3/4 rotors with out extended arms, 1-2 inches inside the plane of the LCA at full lock, making it turn more like Exxon Valdez than the Sh***y Kitty.
however, I’m also pretty sure from careful analysis of pics of trucks with them and how the wheel is better centered in the wheel well, that they are not simply extended out, but also relocate the ball joints and thus wheel farther forward about an inch, which would mean they must be narrower in that area, but not as much as I was originally thinking.
however that still doesn’t help much when you move the lip of the wheel farther in towards the truck center and CA by 3” (assuming my guess is correct) but don’t move the barrel out away from the CA by 3” with a 22 vs a 16. (6” total ergo 3” farther away from center)…
if my guess is right amd they only tuck them 1.5 that would make a difference, but I’m not sure it would be enough to allow a 16 as it’s more moving the pivot point this making the wheel a lesser offset (more backspacing) that would seem to be the true issue.
I might be totally off base here and maybe you can run a 16 with lowboys, but if so I’m guessing they are narrower CA, not extended CA, ie, you stay 1 ton rotor.
from what I’m looking at (having these massive windows in my alcoas does help vs the small circles faces) amd what I extrapolate from it, I’m pretty sure mmw is right in didcating that you have to have 22s to run extended arms with 3/4 brakes, and since geometry shouldn’t be massively different, that would apply to lowboy as well.
though I bet with the tubulars you could probably get away with 19s and maybe not Lose a lot of steering angle at full lock. By comparison.
I’ll try to get some pics in a bit, but hard to do with a phone in one hand and a yardstick in the other, lol.