Nice work & car HWYCRZR!
Couple things on the 300. Hopefully you relubed the front bearings when the brake job was done. You should also look at & grease the rears as well. The old grease gets petrified & wipes out the bearings. Normally just remove axles & clean out grease with brake clean & relube bearing using a needle attachment to grease gun. Change inner seals, new gaskets & set endplay with adjuster.
Also, you might want to remove the lower aluminum trim, especially the quarters. Dirt tends to collect inside & when it gets wet it promotes rust. Just remove lower screws & push up as gently as possible so as not to break the clips which will be fragile. The clips are hard to find but can be bought here-
65-68 Rocker Moulding Clip-Repro