I've now got a 305 superhawk front drum and a 450 front drum. The 450 seems to have the rep for the best of the two. But I've examined both closely now and it's pretty much the same brake. The 450 has 40 spokes to the 305's 36 of course. A moot point on a rim laced with modern spokes. The actual shoes are the same...so the 450 has no more contact area than the 305. The DLS linkage appears to be the same so the leverage ratio is the same. And while the 450 has a rivet in clevis for the shoe pivot that can't be replaced if it worn or loose...the 305 has a bolt in clevis that can be replaced. The 450 has a washer and cotter pin holding on the pivot side of the shoe...while the 305 has a nice square headed bolt that passes through the pivot end and threads into the backing plate with a jam nut on the outside...a better and stronger setup to me.
The 450 hub is a bit more heavy duty...making it stronger than the already very heavy duty 305...but there is a weight penalty for that.
The 305 hub and parts seem a whole lot easier to come by.
Anyone using a worked CB160 brake that can tell me how much better it works than a stock 160 brake?