Clutch adjustment problem!!

I am having a devil of a time getting my clutch properly adjusted. Here's the situation.

-Brand new rebuilt T-5 done by reputable local tranny shop. ( I did the R&R on the tranny myself )
- Brand new King Cobra clutch, Ford Racing quadrant and adjustable clutch cable, NO FWA.
- Used B&M short throw shifter from my old tranny. Worked fine on old tranny.
- Full synthetic Mercon ATF

- I finally got the clutch adjusted to what I think is "zero lash". If you manually press the clutch pedal, it does not get stiff until it is even with the brake pedal. Clutch engages about about 1/4 way off the floor. I am happy with where and how it engages.

- 1-2 shift is fine, 2-3 shift is fine but it grinds going into 4th and 5th.
4-3 and 3-2 downshifts are fine. No problems with reverse. This is with normal driving - no power shifts.

- I was thinking of loosening the clutch adjustment some more but I really would not want the engagement point any lower to the floor.

- Could this be a shifter problem since it only grinds 4th and 5th??. I had no problems with the same shifter on my old tranny.

Any ideas what the problem might be?? Should I just keep loosening the clutch adjuster??

Thanks for the help!

EMW150- I had the clutch tighter/higher and it would soft grind 3 and hard grind 4. With the clutch a little looser it soft grinds 4 and 5. I would loosen it some more but then the engagement point would be on top of the firewall!!

Well I spoke to the shop that rebuilt my tranny. He said that it sounds like I have the clutch pretty much properly adjusted.

He said to bring it over and he will take a look at it. Tranny came with a warranty, so I will see what he says.