I know what you mean, '73 SG here 8)
The pickups in it arent stock, the stock were black mini humbuckers.
I now have Gibson classic '57 paf/ classic plus paf(have alnico II magnet) in it and it sounds dark and woody but still has cutting high mids.
If i would not have those doing nothing i would get a set of stormy mondays or the hotter Mules with alnico II magnet. I have the mules with alnico IV, but they worked out better with 500k pots in an LP and i wanted to keep the original 300k pots in the SG.
Alnico II pickups are the bomb for oldskool grinding, the nice organic kind of grind, they just love gain, also can get very thick and wide if you want it to be.

My '73 SG with (then) raw nickel Mules