[cas3]

Reviewing, I did not answer the whole question. The stock manifold would have a vacuum port near the front for the dizzy. You mention "97's" , so I assume not stock, but still should have a vacuum port somewhere. The crab dizzy is a vacuum brake , not for spark retard as in modern gizmo's. I've not done it, but I read some folks lock them down to be turned off basically, as the modern gas and generally low by modern standards compression does not care. They have internal mechanical advance . I'll stop there, lets hear from some ignition experts lest I spew more incorrect information