Cranking difficulty with advanced timing??

[slikside]

I just advanced my timing from 8*BTDC to about 16*BTDC to try and get some better performance and fuel economy.

Now, when I go to start it, even cold, it struggles to crank over, similar to a heat soaked starter.

Should this be expected, or is something else going on coincidentally?

This is on a bone stock '72 350 C-10 with points ignition.

The throttle response is definitely better.

Thanks.