Bad MPG. Timing off and No advance on my HEI

[rscam]

I posted a dissapointing MPG thread a few days ago. Just to let you know. I checked my timing and it has moved to about 20 degrees BTDC. I have no advance on my dist. I guess it should have about 34 degrees @ 2800 rpm with the advance unhooked. I reset the timing to 8 degrees BTDC and I have no advance with the vacuum hooked up or not. It stays at 8 degrees no matter the rpm. I have the L-79 cam which is not known for MPG. How do I fix the advance problem. Its an HEI dist.