I am back at it again!!! Question?

[frasern]

I would have to get a new drive shaft and maybe move trans mount

This is a little simplistic. The Lincoln has a double insulated trans. mount, two pedestals to a cross bracket, with 4 rubber mounts. Very unique. Tailshaft is also very unique.
Factory advertising states the '61 transmission was re-designed to fit the much smaller floor cavity, I think any transmission swap will require re-working the tunnel. As I said, anything can be done, but enter it knowing it's a big job, expect the worst.
$10,000+ for a rebuild sounds high, but not unbelievable depending on the extras, a stock rebuild should be cheaper.
As I said, I am not an expert on mods, but a '68 460 with a Lincoln C6, may be cheaper and easier, and a lot more aftermarket goodies are available. Floor work is still likely, but a '68 floor piece can be grafted in easier than fabricating from scratch.
It's easy to say what can be done, a lot harder to do it. Maybe you can look in the pictures gallery, and contact people who have posted their swaps. They can help you better than I can.

Edit; The 460 also has 2 bolt patterns, to fit either a slanted Lincoln C6, or later flat top one. The Lincoln bell housing is smaller, to fit the unibody firewall, and clear the heater. (Yes, I know that's not a firewall)

[tomo]

I would look for a remanufactured engine from suppliers like Jasper or S and J. They can usually beat the price of a machine shop and the warranty is usually better. I have used several Jasper engines in the past and they were easy to install and ran great.

https://www.sandjengines.com/product/1958~~~3458

[TonyC]

I have very serious reservations about those recommendations to use engines that were never designed for this type of car. Such recommendations are usually offered with no clue to the structural and powertrain mods that are inevitably involved...and even those few who may have actual experience will deceptively avoid talking about the effort and cost involved. Basically, what you think you're saving by going with a common engine will be spent, and then some, just trying to get the bloody thing to fit. Recall my earliest post: Nothing with these cars is a simple "drop-in," not unless the component being dropped in is identical to the component being dropped out. Even the 460 required structural mods to these cars, which I suspect contributed to integrity compromises...that is a major concern with modding these cars, one that hardly anyone thinks about. You cannot do the same mods to a unibody that you can do to a body-on-frame, not without serious consequences.

If you have the drug income to do it and spare time on your hands between deals, then it can be done. If you're an upright citizen who as a consequence has limited income and needs to do your restoration on a budget, ditch the Vin-Diesel ideas. Your replacement options are extremely limited with these Lincolns; they ain't Chevys, and must never be viewed as such.

--Tony

[tomo]

I agree with Tony, once you start to do your own engineering on a Lincoln, you are asking for trouble. If you want a reliable driver, stick as close to stock for your year Lincoln as possible. Make sure that any modifications were done by someone that will stand behind the modification and is able to repair or replace thee modified parts.