My 340 build

The Voodoo although it may turn out to be too big or may not
same duration as the 274 comp but look at the difference in the lift- makes a big difference in power
will require correct springs
the 274 comp will leave HP on the table and so will the 268 but even more so
268 might have to much dynamic compression with your build, or may not
both are comps are "universal" one size fits all grinds
Comps XE274HL is the one that more closely matches the Lunati and is designed for MOPAR
sell the 268 to someone who wants to detune his Mopar
save the 274 comp- it could be reground shorter with same lift depending on how your motor turns out and how you want it to drive (with your gears and converter etc)
but get a few miles on the lunati, run a compression test and let us know how it's going