JMG2

the hellcat is more or less the same size/dimensions as an LT5 -- thought the lt5 is slightly more compact. They're both supercharged 6.2l motors, similar same power. The hellcat ... even the "hellephant"... isn't a monster motor, it's mopar's version of the venerable smallblock. hte LT5 weighs just under 600 pounds.. I searched for hellcat's weight, but keep coming up with vehicle weights, I can't imagine it weighs much more than an LT5.

But that begs the question.. even a used hellcat can be sold for around $15k or so. You can pick up a brand new LT5 for right around $20k. Crap, you can get a supercharged turnkey lt4 from jeggs for $16k.
*fitting* the hellcat into the 'vette won't be the issue-- it'll be everything else. Interfacing the computer to.. just about everything. adapters for the transmission. I doubt anyone makes those, so it'll take some significant fabbing.

Not trying to rain on anyone's parade, if you want to attempt it go right ahead, just seems like you're in for a lot of heartache when you can get something (with a warranty no less) that gives you similar performance without having to build out everything else from scratch.

bikeriderga

I have to agree with the others that suggested getting a Mopar to drop that engine in or swap sell to get an crate LS3, LS7, LS9, or one of the newer LT motors from Chevy performance for your C5.

You will spend a lot less money, not have to build custom mounts, cross member, and who know what else to mesh it up with the C5 drive train and ECU.