LA small block timing is suddenly way off

Ditch that MSD for testing. Id grab a points and wire it up. I know an ignition box isnt going to throw you off 30 degrees but F'n with an MSD with a standard timing light is not easy. Jumped chain will also cause valve timing issues. Just pull the cover. Ita about 30 minutes of work and peace of mind. 5psi is fine for an edelbrock.