318 2bbl won't idle without choke

I just tried giving it a ton of advance - it started slightly easier but not much. I ran a compression check and got 100-115psi on all cylinders, which should at least be ok enough to run.

If I turn the crank back and forth at the harmonic balancer, there's about 10 degrees of slop between it and the distributor rotor. Maybe my timing chain has stretched?