If you keep them full length and are shooting 175gr up front (point & insert) I think there's a good chance the 400s would work for you. I don't think you'll ever make 340s work and be close to the weight you want.
Since you know the ballpark weight range you want your arrows to end up at, just work backwards to find your shaft. 425 gr - 150gr point = 275gr - 46gr for components (insert 25gr, fletching 12gr, nock 9 gr) leaves you a 229gr raw shaft. 229 / 32" means you're looking for an arrow that weighs around 7 GPI. That narrows your shaft choices down pretty quickly and rules out most arrows with a wood grain finish.
You might take a look at the Black Eagle Spartan. It's a small diameter (same dia as the Centershot) and weighs right at 7 gpi in a 400 spine. If you want a micro diameter the Black Eagle Rampage has about the same gpi.