1972 Demon 340 engine mods

I plugged your numbers in, and at 330ft elevation, to make 130, the Scr needs to be 8.6
To make an 8.6Scr, the Total chamber volume needs to be about 91.5cc..
To make that, with 71.8cc heads, an 8.8 gasket and 5cc eyes, leaves 5.9 in the decks which calculates to .024 pistons down.
You can put closed chamber heads on that with an .028 gasket for a Q of .052, that's pretty good. So then adding the 63 and the 6.5 and the 5 we get a new Total chamber volume of 74.5cc and a new Scr of 10.33.
Ok now with 10.33 and targeting 185psi for aluminum. the ICA would like to be 48* for a Whoppingly strong VP of 164. Unfortunately a cam like that is 318 2bbl cam, so that will never fly.
The calculator wants an exact Advertised ICA to be accurate but with a solid cam that's always a guessing game especially from Hughes who doesn't publish the advertised numbers. So I'll have to use a best guess on that [email protected] cam. First I'll gross it up by 38* to get a 272*. then I'll crank in 3 more cuz Hughes doesn't measure at .006 but rather .008, for a gross of 275*. Then I'll lose 3 in the lash and end up with an estimated 272* net. Ok from that and the 104 install, that calculates to an ICA of 60*. Now plugging that into the Wallace, with the 10.33, I get Dcr of 8.49, and pressure of 167@ a VP of 137, about 3 points better than a stock 1969 9.2Scr teener.
This will burn el-cheapo gas with those aluminum heads.
This will make good power after 4000
The bottom will be soft in comparison; it will feel like a good 318 below 3000.
The power band is not the best for a 3 speed stick, but the 108 LSA will bring in good numbers. For a streeter it should be fun
It will probably needs gear in compensation for the low VP, and the large splits.

Now remember, this is all a guessing game right now, because
A) the 130psi could be because of an 18% leakage off an actual 160psi engine.
B) I used flat-tops in the holes, with 5cc eyebrows
C) I guessed at the cams ICA
D) I guessed at the head volume
E) I guessed at a lotta numbers.
F) Warsaw is only at 330ft