[MEDIK418]

Hey, since you asked, here's one I learned long time ago. Before I go too far, I've never been able to easily powershift a T-5. I don't know whether they're too notchy or I'm too notchy in my advanced years but here goes. This works like a dream on most every transmission I've ever tried it in and it does work most of the time on T-5's that I've tried. You just gotta get the timing down right.
Power shifting shouldn't hurt too many things until you miss a gear. 5 liter engines rev really quick and an over rev can be costly in an engine that revs that quick especially one that you've redlined before you did that. I was told years ago by Carrol Caudle (multiple world championships in D-gas in the 60's and 70's) that manual transmissions should never be hitched to a big block chevy for this very reason, they rev too quickly to recover from a missed shift. 5 liters don't have the valvetrain problems that BB chevies do so there's some hope.
If a transmission is under a load it's all but impossible to pull out of gear. . .all agreed? If you cause any kind of lapse in the power going to said transmission while trying to pull it out of gear, even for a microsecond, it'll most likely pop out of gear. Quite easily I will add. I learned part of this racing motocross in my younger years, never use a clutch unless you're gonna stop.
Try this, as you start your shift, put some pressure (don't break it, just pressurize it a little)on the shifter in the direction you're going to shift. As you push the clutch in you should feel the shifter pop out of gear. (and I mean about as soon as the clutch pedal starts to move it will pop out) If you time the shifter movement right and are quick enough and most of the planets are aligned just so, . . . by the time you get the clutch pedal to the floor, the shifter should be going into the next gear. THen it's just a matter of the clutch pedal returning to normal flight and forward motion should be unimpaired. Do this a few times while NOT going great guns before you decide to try it under a big load at a rediculous rpm.
Like I said, popping one out of gear is easy, If you get the pedal to the floor fast and time the final throw of the shifter into the next gear you should have the clutch at full disengagement about then. Don't worry about letting the clutch out fast when you first try this, just ease it out and see iif it indeed went into gear. In actual practice, you'll be slamming the clutch in and out so fast you won't know if it hit the gear till it's either too late one of two things happens. . .you hung a good un or your rev-limiter just got a workout.