Only runs 40 Degrees advanced

I did not know the math but I agree with you. That’s why I pulled the timing cover to check the alignment because I thought that is the only thing that could’ve given. But when I did it was still dot to dot lined up and I was expectIng that to be off or a keyway to be Sheared but everything looked fine. But I have to agree it is somewhere in the cam timing I may have to take it out to find it.
You did say your chain was loose before you added the tensioner?