I just installed a 94/95 cobra computer in my 95 gt last week. I did that along with installing the correct sample tube for my MAF. My purpose was trying to improve the quality of my idle, which it did help. My mods are similar to a cobra and that was my thought behind it.
The cobra came equipped with 24lb. injectors, but still used the same MAF as the the gt with the 19lb. injectors. The cobra's computer program was calibrated for that setup. You must take that in account with your setup or up may have an air/fuel ratio issue.
I don't know if you'll see any performance increases with the computer. I would imagine that the cobra would have done much better than 25 hp gain over the gt with the 24lb injectors, better intake, gt40 heads and 1.7 roller rockers. The comuputer's program could have written with very mild settings.