I had SAM machine/repair heads and a block from a dexcool ravaged 3.1 with over 200k on it. I got the completed heads along with the block, crank camshaft master rebuild kit and went to work assembling my engine. During the assembly process I ran into a few snags with fitting the camshaft as well as one exhaust stud hole repair that got overlooked on one head and they went out of their way to take care of me. Having installed my completed engine, I ran it through the break-in and became concerned with some smoking at start up. It was heavy at first but it seemed to do better and better so I let my wife drive it to work and she reported that she hadn't noticed any smoking at start up but after the first oil change I noticed that it was still smoking at start up so I gave SAM a few calls but got no answer. I decided to have a look myself yesterday so I pulled the plugs - they all had oil/carbon on them to varying degrees so I pulled the valve covers/rockers and using a cyl pressure differential tester to pressurize the cyls I pulled the spring from cyl 1 exhaust valve and found... NO SEAL. As I continued, I found almost EVERY seal on the remaining valves, all the way to cyl. 6, ripped. (See included pictures) Never in my life have I received completed heads from a machine shop that weren't ready to install an run in every aspect - I didn't even occur to me that I I should have to check something like that. So far, the machine work seems to have been spot on and top-notch but I can't even begin to describe my disappointment here. While it did occur to me to seek resolution through Stamps, I considered two things, 1. I was already into it. 2. Considering the kind of mistake, I wasn't excited about trusting anyone else to make this repair - this happened to me, an experienced and tooled technician but good god man, if I would have had to rely on them to fix this?... I mean, I've spent a long time in the business and I've made a few mistakes myself. It happens - no one is perfect but C'mon, valve seals? It runs great and I appreciate SAMs exceptional machine work but I can only give 3 stars - wish it could have been 5 stars.