I just completed a 4.6 swap in a 61 Sunliner. I am happy with the results, however, there are some issues that you need to address with the 4.6 that you wouldn't with the FE block. If you want simple, stick with original. If you want more performance, you have options like going to a modified 390 or even a modified small block Ford like a 302. When you switch out the engine/tranny, then of course mounts, driveshafts all become issues.
In the case of the 4.6, some of the issues you will come up against: Engine mounts, tranny mount, you will need to convert to a front sump oil pan, add electric fuel pump in the tank and run fuel lines, modify driveshaft for correct length, correct rear joint, then deal with all of the electronics/wiring.
Going with EFI in my opinion was worth it. Car runs good, is reliable and I love the overdrive. I think one of the other unique things about this conversion is that I am the only guy around here running that type of drivetrain, it draws lots of interest, curiosity. I enjoy conversing with others about the swap.
I have posted numerous threads on this site about this swap. If I can be of further help, let me know.

You will definitely have to change intakes if you want to be able to close the hood on that car with the 4.6. As far as what is involved in changing the intakes, I wouldn't be able to tell you as I just don't have enough knowledge. You will need to run the ECM from the F150. I think the truck used knock sensors, the Crwon Vic did not. Ford changed sensors often between various years and models, so you need the correct ECM or your going to be dealing with all sorts of codes when you fire it up. Another option would be to fork out the cash for a wire kit like i did. The time you will save not having to harvest the wires you need out of the OEM harnesses is worth it. 
Just a question because I am curious...if gas mileage is an issue, why then are you choosing such a big car for your wife to use as a daily driver? Why not get her a Mustang GT for example and get over 30 mpg all day long?

I see, she wants a classic. Cool. I said the same thing about the price of the wire kit and tune when I first started looking.."ouch". However, it was worth every penny! Now that I have done it, harvesting the wires you actually need for the swap would be pretty straight forward. But with the kit, it sure makes it quicker and neater. Each sensor plug comes with 20 feet of wire, so you can mount the ECM where ever you want.
I also forgot to mention some other stuff you will need to deal with: Throttle linkage, tranny linkage, different size rad hose outlets to factory radiator, radiator overflow tank, air intake system are a few more that come to mind. 
I'm sure you would be happy with the 4.6, just a little more effort to get there.

Since you have to put an intake on it any way what if you went with a carbureted intake like this one

And then you could run a carb for a while to get any bugs worked out of the car and get it on the road for much less time and money.  Then after she has driven it a bit an easyEFI kit or other carb to EFI conversion would bolt rite up.  

Boogyman wrote:

dan73 wrote:

im also considering an LS.

Blasphemy!


 

The LS is not blasphemy if and only if you put a transmission out of a MoPar, suspension out of a Cadillac and interior out of a Subaru

All joking aside I am a little bit torn.  I can not argue with the performance and availability of the LS series of engines.  There is fantastic aftermarket support and I  have no doubt the swap could be done well.  Being one who modifies everything I have to respect the engineering involved in transplanting the "heart of a cow into a horse".

With that said I am a little turned off to a Chevy engine in a Ford due to all the Ford hot rods running around with Chevy 350s in them.  

No matter what you decide I look forward to hearing all about it here on the forum.