I would also recommend a tear down and inspection. I also purchased a used but what seemed like an awesome running 426 Hemi crate engine last fall. This engine had great oil pressure (65-70 psi) cold to hot and the water temp held steady at 180 degrees once warmed up when tested in the car that the engine was in. We ran this engine for nearly 45 minutes. Even so, knowing these engines had issues a full tear down for an inspection was in order before installing it into my Charger. No major issues have been found but lots of small issues that left unattended would have resulted in bigger problems in the near future. So far we found one of the lifters snap ring in the oil pan and another about ready to let loose. The bronze intermediate shaft bushing was seized to the intermediate shaft. The timing chain was stretched. The engine was obviously put together dirty as all the main and rod bearing had lots of very tiny scratches on them. Also, this engine had a windage tray installed and 7 of the 8 rods have hit the windage tray as we found very small scuff marks on the tray. Next is the tear down of the heads. I'm very happy with the decision to tear down and inspect this engine. For the small amount of money I'll be spending to correct these issues I'll feel confident knowing that everything is up to par and it will reduce the chances of having to pull the engine back out anytime soon.