318 2bbl won't idle without choke

Yur timing is IMO lying to you. Crank in the ignition timing and close the speed screw until the throttle blades get back down on the bottom of the transfer slots, and the mixture screws start working again. Then check the manifold vacuum . If it ain't over ~16 inches at 650(N/P), then check the cam timing.
If it is over 16, then prove the index TDC is true TDC #1 cylinder on compression stroke.