I wouldn't go single plane, it will give up too much bottom end power and a 273 gonna have a problem with that anyways with being so small, cam gonna be a tricky choice too, want something that will make great top end power 6000-7000 rpm but sacrifice as little as possible down low power. Need to make the power more from the heads than cam, like 4.8l LS engines do they make good 2500-6500+ power with small ish roller cams 215-225 because of the LS head. Carb wise if making 350-400 hp don't see no reason you can't run it.