Thanks and yes for rear no for front. I explained above. I'll repaste here:

"on the rear stock spring height is perfect for the 28.8" tire. Front is lowered about an inch with my coil overs"

I understood they were stock springs just not sure if they were "new" stock or "Original 42 year old" stock springs that have sagged over the years. Thanks for the clarification. I wonder how much they did sag/ drop vs. a new stock spring.

I just ordered a 2" drop spring from BMR, I hope they aren't too low. If they are I could add a little air in the air bags to get the height I'm looking for?

I think you should be OK if you put about 10 lbs in each airbag. I run those too (about 5 lbs each). That will also help with backseat passengers if you ever have them. If you ever go to the track you could also leave the drivers side at 10 and increase the passenger side to somewhere between 15 -20 for preload. My only concern is those 305/45/18 tires are almost 29 inches tall. If you get the tire too far tucked up into the wheel well, it gets skinnier and skinnier. Only one way to find out. Good luck! It definitely takes some trail and error to get everything dialed in how you want.