160 degree stat won't change a thing, If ya got a 195 in it and its workin proper that means its wide open at 195, A 350 bored 60 over is gonna run a little hot, I don't like a motor specially mine to run over 180-190, But apparentley the auto makers seem to think it's o.k. as most all of em turn the electric fans on at 226-228
In your case I think I'd be lookin at a more efficient radiator such as a Griiffen aluminum......