My manuals for '65 thru '67 say .017 and the one for '68 says .021 like Slim said. That is for single point setups. I've always set the points for dwell so the coil can have max. time to do its thing (thats why dual point systems give better torque -- they let the coil build up more before it empties into the cap when the point combo closes). For '65 through '67, 289 single point, dwell is spec'd at between 26 and 31 degrees. I tend to set it at 30 degrees. More dwell = more torgue. I don't bother with gap really except to check the points every month or so and clean the surfaces. Gotta make sure not to set 'em too close or they'll burn faster than average. If you dont have a dwell meter, .017 works just fine.