Friend of mine just bought a new to him challenger. Left engine was rebuilt two years ago. Right engine is original. He got it home and the right engine would only engage the starter, it would not turn over with spark plugs in it. took plugs out and it turns over, so I thought starter was weak since battery is good enough to start the rebuilt engine. Installed new starter and the same problem persists. It turns over slower with the plugs out of it than the other engine turns over with the plugs in it. Anyone else ever run into this problem? Its not hydrolocked, we turned it over plenty enough to clear anything out of it.