Base timing. Really ?

Great info !
Just a note. With my cam I would say it will idle higher than 800. Prob 900 or a touch more.
My distributor is prob a late 70s smog job. /. MSD box on the inner fender.
So
Base timing , we are close. 15-18 ish
Leave springs alone , or lighten the primary spring
Don’t touch the secondary spring
Limit the plate to ,say 35 ish. ( 8-9 degrees at the plate )
Yes ?
I know this is taking a lot for granted, but I would like to be as close as I can to start. You guys have a ton of experience. Gold.
Thanks
so even with our cams we are running, we should retain the factory elongated spring and change the other one out for a lighter one?