Don't know where to start with all this so I'll just start. I've got a 1950 Streamliner in desperate need of some more cubes. I'm looking for a solid Pontiac block to get started and am realizing the 455 I thought I'd use is becoming hard to find. They're out there, just pricey. I'm not in a huge hurry so I can spend a little time to find the right block but was wondering why so few 389's are used for mild performance builds. There seem to be a lot of them. There are a lot of 400's as well and that might be where I go. Still I'm wondering, is a good 389 a bad place to start?