I've used 2 machine shops in the Denver area. Havana machine on a 383 mild engine and Ridge Reamers on my current 471. Both were good for me. However, if you re going for a larger hp engine, I'd go with Ridge Reamers. Pete's been working on Mopars for a long time. He had a Mirada w/383 into the 10's at altitude. So he has the first had knowledge on what's needed. Downside is that you have to preplan your build as he is very busy. Call now for a build start time. I can tell you it will be worth it.