This has been discussed a million time on here
Radial tire side wall is toooooooo soft. Bias ply is stiffer ( less hop in corner)
The rear tire has way more tread also is a flat not rounded profile
Just get a rear tire that is the same size as on the front. You are not changing rim just tire so you need a tire the same size as you have only a rear. This is obviously a tire that belongs on a different bike.
U don't have to do anything you can wear out a Dunlap tire every 7,000 miles if you like , or switch to a Battleaxe or a Venom or a Pilot Activ. Rear tire And go 20,000+
Mount it anyway you want. The reverse rotation is only a theory.