If you mean printing useing a plastic fillament,then probably no.
If you are refering to 3D printing useing laser sintered titanium,then probably yes.
Very very nice.Even if the 3D printed material is not strong enough to use as a final product, it can be used to create a model for casting aluminum. That might work for you and is much cheaper than 3D printed metal these days.
is then cast as this
If by 'G' you mean the ground power unit crank, the flange needs to be reinforced even in the O290, when it's installed in an a/c. I'd be really leery about it if the plane is going to do acro.Yes, you can build a (cheater) 320 using a 290 D2 case with the cylinder holes bored out 1/4" (not 1/8"). I've done that. Two things: It has to be a D2 case, not a D or G because you need hydraulic lifters which the D and G do not have. Wide deck cylinders won't bolt on, only narrow deck ones. Some of the airboat guys use 290 G (narrow flange) crankshafts to save 3 pounds. I believe that the G crankshafts are actually 235 crankshafts. I have a rebuilt G C/S if you're interested. For building a carbon sump you need to use special hi temp epoxy of course. When you paint, only 1/2 the weight of the paint stays on whatever you're painting. The other half is lost through evaporation and out the exhaust fan.