Engine/Tranny Swap

I have a 1988 Ford Crown Victoria with a 5.0L and an automatic with overdrive, which recently the overdrive blew, and then the drive. It is definitely shot. I found a 1987 Lincoln Mark VII with a 5.0L H.O. Motor and also has a Automatic overdrive tranny. I am not positive if the tranny is good yet, but if I find that it is, I was wondering if anyone could tell me if the Lincoln tranny will go into my Crown Vic without any modifications and how easy or hard would it be. I may even use the Lincoln Engine, maybe not right away, but I am wondering the same thing about that; how much trouble would it be to swap it into the Crown Vic? Any insight would be great.