While I have not had any personal experiences with engines from them a buddy of mine bought a 408 from them two years ago. Two problems I saw firsthand were several oil leaks and a bunch of failed hydraulic lifters. Valve train clattered so badly he pulled engine and sent back to them. They made some changes and sent it back to him in Canada at his expense. The other problem with his 408 from them was I could eat it with my 340. I understand not everybody has the same budget, I suggest you custom build the very best short block you can afford then add better top end as you can afford it. Not trying to ruffle feathers just stating my opinion.