Today, in modern times, we have become a bit numb to all of the Hellcat power figures, it seems. FEW people realize what it took to make 400 horsepower when your car was newer, much less now. Additionally, with a heavier car (usually considered to be over 3500lbs, as I recall), with a "street/highway" gear (as the 3.23 is), it takes TORQUE to get the car off the line quickly. Something else that a modern car easily does with a 4.70-type low gear in the 8-spd automatic transmission, vs the TFs 2.45 low gear.
All of those big power number engines everybody seems to desire to build these days, as modest in power as they might be in comparison to the Hellcats, can be "not much fun" to drive on the street as all of that big power only happens near 5500rpm. Not an rpm range normally seen on a street car, by observation.
In general, though, aim for a cam of similar specs to the 340 LA V8. Then add a modern 650AVS2 and any 4bbl intake you might like, similar to OEM stock (Edelbrock Performer, for example). Then a torque converter with a stall speed just a bit higher than what that 340/275 motor had. Can't forget the Mahle pistons with the "MM" ring sets! That, to me, would be a nice street car and be credible on the strip, if needed.
The narrow rings unlock a good bit of power that friction would otherwise consume.
To go farther, you'll need a stroker rotating assembly, for about 408cid. There is a Nick's Garage video on such a stroker 360 that made 425hp on his dyno, that was in a 'Cuda of one of his customers. Quite impressive with the stock cyl heads!
Just some thoughts and observations,
CBODY67