Old technology doesn't always equal poorer performance. The GT40 intake is an old design. Mayeb the oldest still living design. And in test after test it is still in the hunt for the top spot. And it has repeatadly beat all comers for lowend torque production, which is extremely importent despite what some people "think" they know. And it's top end horsepower is within a couple hp usually, if all other parameters are the same. I posted numbers from the best intake comparison published yet (IMO) on the subject in another thread and I also averaged some numbers. Results were the GT40 is still impressive after all these years. More so than many of it competitors.
As for the SSI, I suspect it'll shine as a power adder intake...ie supercharger or turbo intake.