Essentially the install is just like using a 230 or a 250 except for the right side motor mount.
The other major difference is the added height of a 292 over the 230 / 250 due to the longer stroke.
That is a non problem in a 39 because of the hood and firewall height. All 3 engines are longer than the old 216 so you will need to get the 292 as far back to the firewall as possible to avoid major radiator interference. As a guide you can check out a 37 or 38 Chevy with a 230/250/292 installed as the engine bays are virtually identical to a 39 exceept for grille shrouds and radiators. Sounds like a good combo, keep us posted!