Well the A14 block and a15 are the same, the rods are the same but the pistons are taller on the a14 by 3-5 mm? (77 vs 82mm stroke) correct me on that one.
However "around" 10mm difference? on the rod length in this case seems that it might not be a big deal in regards to the a14 crank.
If 1600cc a13 are possible then a 1420cc a12 seems more than reasonable.
Time will tell and we hope it works out for Dodge as we do for feral in his crazy challenge but hey feral use argon next time ;).

Everyone put down my uncles project of a 427 cube windsor. Specially since he had to use modded 400 cleveland crank, chrysler 360 hemi rods (just 150mm long) and custom pistons and clearanced w351 block, home made harmonic balancer. But that engine ran for 18 years without a hitch and made around 440 hp and 13.4 second quarters in an old f100.
The rods where too short according to calculations but it didnt stop him embarrassing many flashy posches and other exotic and "correct" machinery.
That thing had a 4 speed manual no auto and the torque it produced was speechless.

If there is lesser dwell time at TDC (which seems like there will be) he might be able to get away with it with higher velocity porting (please read: not larger but better angled atomised fuel delivery which is a slightly cleaned up a12gx head) and maybe some fancy timing setup (higher energy ignition and why not some greenfire plugs as well ;). Also this setup will maybe require a harmonic balancer for the side thrusting (as Dodge did point out to me that he was fully aware of this).
In the end we will see.

For Dodge, this exercise will beat a non factory non engineered a14 in costs hands down. Lets not forget originality.
Bring it on I said ol chap

Harry thanx for those calculations it will be interesting to see if it is 1.57 or 1.6 with exact measurements and whether it matters in our much loved A series and not small block v8s.