I understand the question....but It aint clear to me, as to how you need to apply the answer.
So FWIW....
Far as diameter, modern 45's are .451-.452, or there abouts...so no problem there.
Problem is though, .45ACP bullets lack a crimp groove....which you'll surely need for working the cartridges through a levergun. That, and a perty-heavy crimp is nessesary to prevent bullet set-back due to the compressed mag spring and/or recoil. One can get around not having a crimp groove though, but it may require some extra work and tooling.
You might also find that the COL of a 45LC round which has been loaded with a 45ACP bullet aint right for a particular levergun...some of which are rather sensative to what length ammo they'll reliably feed.
Nothing to do there but try it and see.
Then there's the accuracy thing. Meaning that every 45LC gun that I've had prefers a heavier/longer bullet than is common to the 45ACP. Reason for that is..... most 45ACP guns have a different twist rate than 45LC guns.
Up close, it may not matter much. But at distance, it becomes rather apparent.
Anyhow....yeah, it'll work.
How well it works will depend on how you load your ammo, and how fickle your your particular gun is.
Hope this helps.
DGW