probably a more like mid 15s in the 1/4 on the mustang. a 94/95 5.0 is the lowest hp 5.0 they made. not trying to be mean just realistic. I would also try to loose some weight you dont need when you go to the track. take out your toolbox, spare tire, extra junk you dont need at the drag strip. fold your mirrors in also like the big boys do= less drag with them folded in
plus like stated before, built trans, turbo, injectors, loose the edge for something more aggressive like a tst or redline box

 

I would go the drag strip and see what you can do, dont rely on the monitor to tell your times. I stacked a downloader on my fueling box on my 05 and the edge never changed on the 1/4 mile thing.

 

I agree, take it to a track and get a timeslip on your truck. The math says you can run mid 14's at under 400hp with a 7200 lb truck. You should be making that if the tranny is still holding. And I also agree, at ~400hp, the tranny isn't liking it. But I of course went down this same road and it was one of the best times I've had in this sport.

Good luck and have fun getting that slip.