Yes keep it stock but two easy things you should change that will make a big difference.
Get an aluminum driveshaft, it's lighter than the steel stock one and since it's rotating mass & before the rear diff you'll get better acceleration.
And more importantly change the mass air sensor with one form a 93 cobra, the stock 89-93 is very restrictive, they upgraded it in the 93 cobra and then in every Mustang in '94 but the 94 has a different housing, The 93 cobra mas is calibrated for the stock GT 19lbs injectors (even though the cobra had 24s, its computer compensated) You could get one on ebay for $69 and it takes 10 mins to change.
You'll feel the difference the second you drive it...
Guess which one's which
Here's the Cobra unit in my '91GT
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