Divorced choke adjustment?

[RatRacer]

I've got a '78 Chevy G30 van but due to the emissions exemption for 1 ton vehicles at the time the 400 cid 4V is much closer to the older engines.

Has one of those divorced chokes - bimetal coil spring that mounts on the intake manifold.

It takes forever before the thing gets around to letting the choke plate open, leaving the engine bellowing rich mixture smoke for a while then once it does start to open it's still running at a very high idle for a while after that.

I did replace the choke spring, no help, and it appears I'd have to make the rod longer to adjust it leaner but I see no way to "unbend" it to do that.

Any ideas besides one of those electric choke conversion kits? I'm getting tempted to convert it to manual, or somehow mounting a light bulb around the choke cover to serve as sort of a heater.