possible clutch issue

I had this same damn problem in my 03 cobra when it had low miles. It wasnt the clutch though. I wound up putting an Firewall adjuster and qudrant on the car and fixed it right up. I see that you have a tko trans as do i. You need a fw adjuster and quadrant for that and you will be good to go. It even said in my instructions with the tKO that you DO need it

Edit: also, you would know if your clutch is goin out. The thing would be slippin if you were in lets say 4th and 5th gear cruisin at a low rpm. When you go into throttle the rpms would start to raise and not the speed

It might be your clutch...but its most likely you clutch cable and stock quadrant that are giving you problems.

First test the clutch to rule that out. Go to a parking lot, put the car in 4th gear. Try to take off. The car should stall immediately. If it slips...then replace the clutch b/c its likely slipping at other times too.

Once you have tested the clutch functionality and its good. replace the clutch cable and quadrant with a quality ford OEM cable. Go to maximum motorsports...they have a universal fox cable for 60 bucks that works just like the stocker. Then just get a good aluminum quadrant and firewall adjuster and you will be good as new.

I would start with the quadrant, they can usually cause a lot of problems with getting into gears. I hear that the MM piece is a really nice one and is great for pedal effort.

If you feel the POE dropping to the floor as operating temps increase, see if your cable is stretching as it gets hot.

Also if you have not changed the fluid recently, I'd do it.

Good luck.