Disappointing Dyno Numbers

Not sure what your exhaust is but your bottle neck is right at the beginning. That 70MM stock MAF doesn't flow very well. I had a Pro-M 77MM on my car which is about double the CFM of the stock MAF. I would have even opted for a 70MM Throttle Body and opened up the Cobra intake snout to match better.

If your tuner can get you 20HP to 280HP I'd say ditching the stock MAF for something that flows twice the amount may get you close to your goal.

Again, your exhaust plays a big factor too. Hopefully you're running long tubes with a 2.5" collector with 2.5" mid pipe no cats and at least a 2.5" cat back.

MAF AIR FLOW DATA (In CFM):

1.Stock 5.0L 58MM (89-93 Mustangs), 606 CFM
2.Stock 5.0L 70MM (94-95 GT/Cobra Mustangs), 815 CFM
3.Pro-M Bullet (75MM), 964 CFM
4.Ford 80MM (Lightnings), 1017 CFM
5.C&L 73MM, 1171 CFM
6.Modified 80MM (Flow Bar Removed), 1368 CFM
7.C&L 80MM, 1415 CFM
8.Pro-M 77MM (Shorty/Supercharged Version), 1543 CFM
9.Pro-M 77MM (Standard Version), 1562 CFM
10.Pro-M 83MM, 1598 CFM
11.Pro-M 80MM, 1612 CFM

THROTTLE BODY AIR FLOW DATA (In CFM):

1.Ford Stock 5.0L 60MM, 526 CFM
2.Accufab 65MM, 616 CFM
3.BBK 70MM, 726 CFM
4.Accufab 75MM, 845 CFM
5.Accufab 90MM, 1225 CFM

To get some of these aftermarket parts to fit you'll need to get creative. This is a Pro-M MAF on my 347 Stroker (see pic). It didn't have the 4 bolt flange the stock one had. They do make 4 flanger adapters so you can install the filter of your choice, I know UPR makes a version.

Yeah ditch the cats, should free up a few ponies.

EDIT - I missed the part that it was in a totally different car. Maybe you can get the new MAF / Filter into the fender somehow.

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