Who's put a hellcat in an A-body ??
That’s a solid answer. Thanks for the info. Looks like I have some more thinking to do before I open that can of worms lol.
Mine is a 76scamp.
Been thinking on this some and had some thoughts. Or maybe it would be more accurate to say I did some daydreaming about what I would do if I was in your shoes. :D
If it was me, the Holley parts make sense. It would allow the 6.2 to bolt in without cutting the firewall and would allow for the stock AC compressor to bolt up. The oil filter would probably have to change but there is a TRX adapter that keeps the oil cooler function. But other than that, it should pretty much just drop into the car. There are other kits that fit stock k-frames but they won't fit the SC intercooler connections without notching the firewall, no AC compressor with an aftermarket FEAD and the oil filter adapter won't fit. Note that Holley's FEAD kit doesn't work on an HC so that path isn't an option in this case.
If you didn't want to cut the floor and a 727 was ok, I would grab the Holley crossmember and adapter mount and bolt it in. The only trick there is the kickdown, only options I know of is a kit from
Bouchillon, build your own similar to that or run a full manual valve body. You could add a GV overdrive to that, but if it was me I would bite the bullet and do the 8HP or T56. It will make for so much of a nicer car in my mind. Yes, it's a ton of work, but worth it IMO.
I would use the stock FEAD as I think it is probably the cheapest, and will fit the best (IMO). Add a stock HC radiator and fan (works for the factory, should cool the motor fine) and the cooling is done minus the intercooler (no idea on that, sorry).
Fuel is the next question. There is Tanks Inc, or roll your own. Holley has a retrofit pump setup but it's only good up to 550 HP. I recessed a Gen5 Camaro pump into the top of a new tank but I don't have it in the car and I haven't seen anyone else do it like that. So the Tank Inc route is probably the best plan. Make sure to plan for fuel hose as well because the stock 5/16" fuel line in your car isn't going to cut it.
Electronics are a whole can of worms. Don't know if your motor comes with a PCM, etc. or not.
Don't forget about brakes and suspension. I am sure an 8.75" would be fine unless you lean on it, and the car should get bigger brakes. Beyond that it's up to you.
Best I've got.
Note that there are a bunch of ways to do this. HDK (HemiDenny above) has a nice coil over front suspension that should get the motor mounted and an 8HP in the car without cutting the floor. But it adds cost upfront. There are many debates about the pluses and minuses about the COC vs torsion bars, not going there. Only pointing it out as an option in case you weren't aware. I will say I don't think a COC and rack and pinion is the only path, but I can't argue that there are advantages, one being that you very well could get the 8HP without the work of building a floor.
In the end it really comes down to what you want and what you are willing to invest to get there. Not everyone wants the same thing and you need to be clear about what you want going into it. Otherwise it can turn into a black hole that sucks you dry.