Are 31 X 10.50 X 15 Tires Unsafe for Front of 2WD ???

[Green Machine]

I am trying a set of 31 X 10.50 on my 68 2WD. The wheels are 8.5 wide with 3 5/8 back space. Pretty large offset to outside, they were on a 4wd blazer.

Truck rides rougher and gets "twichy" on the front unless road is real smooth.
They do need balanced, but they are going to be driven by my 15 year old son soon to get his licence.

We like the looks and how the fill up the wheel well, but I don't want him to wreck a newly restored truck or get hurt because we put too big or the wrong tires on there.

Please offer any suggestions here - Thanks.