This swap is very do-able...
When I still had my 84 Celebrity wagon I wanted to replace the weak 2.8 V6.
Somebody on the A Body Forum posted a pic of a Pontiac 6000 with a 350 Chevy.
This really got me interested... And I started to do some research.
I found out that it was done with a kit made by a guy named Archie...
He makes them for Fiero swaps... Well the kit alone is 950 bucks (OUCH)
So I started to lurk around on a few of the Fiero Forums and found out about the ability to use the Caddie 4.5 and 4.9 engines.
These engines use the same tranny bolt pattern that is used in all the front wheel drive GM'*, Fiero too even though it is a mid engine it uses a FWD type trans.
The 4.9 is aluminum and is almost the exact same weight as a 2.8 so you don't have to change the front springs due to a heavier V8.
You dont need to change the cradle or the trans... but you do need a donor car for all the computer stuff etc.
I was going to look for a rear ended 91 or newer DeVille.
Or you can do a "Dumb" car, using old school "coil and a carb" setup.
Some where I think I have some links to how to do the Dumb system using readilly available parts.
As to the sound... with Flow-Masters a Caddy 4.9 sounds just like a 'Vette.