3074S M/T, a confusing and frustrating happening

[Adger Smith]

Do those MT Tire grow much?
I am looking at the MT 3073W 31.25/12.2-15W
to replace the 14.5 X 30.5 Goodyears that I had on My SS/DS.
I need a little taller tire, but can not go too tall due to wheel well issues.
The GY's were 96.25" roll out these MT are 98"
The GY's were an old Comp tire ( I think they were 1702 or 1902) with stiff side walls that is discontinued.. It worked
The MT's have the L-8 compound that is toward the soft side.
What do you guys think.
Anyone got any input on this tire?
The only other tire I have found in the roll out and size that might work is the Phoenix 13.0/31.0-15
13.4 tread and 96 roll out...Will take a small gear change