Rhetorical question

I don't exactly agree.

The rear end swap isn't worth the trouble. You would need a shop you could really trust to get the pinion angle right when they weld on the new spring perches. If they need to shorten it then you will need to buy new axles as well.

Are you planing on keeping the EFI or swaping it over to a carb and then transplant it ? If you are going to do the EFI, I'd say go for it but only if you have the experience required for a heavy duty project like that. If you are going to keep it carbed, don't bother with the swap.

As for the AOD, it should be a 4 speed as rbohm said. The trans would definately be a nice upgrade from a C4, but you could provably sell the Crown Vic and get enough out of it to pay for the entire AOD swap instead of having a car that will be hard to sell siting in your drive way. I think all in all it cost me (or should I say my friend) less then $1800 to do my friends conversion which included a complete performance rebuild on the trans, brand new custome drive shaft, shifter linkage conversion parts, lokar TV/trottle brackets and trany crossmember/mount. I'm sure you could get a decent amount for the hole car.