Check and make sure the front passenger side coil spring is seated. I had the same problem and felt inside and could feel that my spring had to spin about two inches more to fully seat. I was going to address this but I changed my engine from a Chevy 350 to a Pontiac 400. The Pontiac engine is sitting more on the passenger side, it seems to have solved my problem.

If you google it you will see that it is common and the front passenger coil spring is the main culprit.