How much vacuum for vacuum switch and TCC?

[K10-Kansas]

I set my adjustable vacuum switch to 7 and 9. Seems like a narrow window but I guess that's normal. I put a 10 second delay relay on there so it won't be cycling in and out of lockup too quickly. I've got a Blueprint 350, Holley 4 barrel carburetor, and an automatic 700r4. While cruising down the highway on any uphill portion my vacuum does drop from 15 to around 7. It seems like I'd want to stay in lockup even if the engine is working a little harder on an incline right? So I should adjust the switch to maybe 5 and 7?


If I leave it at 7 and 9 I guess I'm burning more gas and the transmission is getting warmer. But if I put it at 5 and 7 would I simply be loosing a little power because the transmission is putting a drag on the engine?

Am I thinking about all of this correctly?