jmc

The sum of the coefficients of $g(x)$ can be found by evaluating $g(1)$. Since $g(x)=f(x+1)$, we know that $g(1)=f(2)$. Therefore the sum of the coefficients is equal to $f(2)=2^7-3\cdot 2^3+2=128-24+2=\boxed{106}.$