318 power?

Oh, dude, you are so screwd...

I used to have two sets of tires(three actually with the DragRadials). One set for city bombing, and then another set for the highway. Now I have overdrive.
For you, the difference from 23.8 to 28 would drop the hiway rpm to 85%. That would make 85mph, drop from 4262 locked to 3622 with 3.55s. Or with 2.76s the Rs would drop from 3314 to 2816. This 85% is about the same as 1.5 rear gear changes which in this range are about 10%.
3314 is awful buzzy. 2816 is ok for an hour or maybe two.
The faster you spin the engine the more important it is to have everything that is spinning well-balanced.Driveshaft,axles,wheels,clutch,and engine guts.Anything vibrating will soon make it's presence FELT.
The tire swap is kinda like an overdrive; which might reduce the rpm with 3.55s;from 4262 to between 3324@78%, to 2941@69%; and with 2.76s, from 3314 to between 2585 and 2287.