FC lowered the stroke on the Hellcat so they could get a 1.28 comp Ht more material above the pin so they didn't have to go high end after market for the piston,
Both the SRT392 and the Hellcat use the same length rod(6.20)

A BGE based 426CI stock 4.09 bore and 4.05 stroke with a 6.125 rod(1.51RR) use a 1.12 comp Ht piston, Arrington, Muscle Motors Xtreme,
Seidle Motorsports, and a few others offer this combo for boost applications...soooooooooooo it must be working.
I'm redoing a Arrington alum block 440 ,4.16 X 4.05 ,6.125 rod 1.09 Comp Ht , Ken Bell supercharger ,after 30K miles @ 10 psi #3 cylinder sleeve split.
Just bought a 426CI based 6.1 short block (4.08X4.08) 6.125 Rod 1.88 Honda journal .866 Dia pin ,had 1.065 Comp Ht JE's everything that every one says not to do .. they did and ran 18psi with a Whipple 2.9L supercharger...since April 2016, 22kmiles on it...split the bore in #1 up at Beaver spring this past May....if you want longevity..this is not your combo, I bought it to see if I can use Darton sleeve Mopar part # P4510316
This past spring we did a BGE based 427CI , 4.125 X 4 with a 6.125 rod a 1.14 comp ht(1.53RR) 4.5L whipple...cracked the Hellcat head...short block was fine...

With todays metallurgy 1.09 Comp ht(1.5 RR) is about the lowest you should go and survive with low boost (6-12) anything higher you should aim for a minimum of 1.12 comp ht.

There are quite a few 03-08 5.7 based "392" pushing 14-18psi with a 4.05 crank,6.125 rods and 1.09 Comp ht, granted it's a 3.917-3.957 piston, smaller surface area, so it'll handle the pressure better than a 4.09