truck rolls back in gear.

[FORDMAN41291]

ok i have a 94 F150 with a 4.9l I6. with a new 11 inch clutch. ok my throwout bearing and slave cylinder are going out. tonight my neighbor was knocking on my dorr and my truck had rolled back about 6 or 7 feet while it was in gear turned off obviously. now when i start it and run it i hear this ticking sound in the powertrain.. is this clutch a POS or why wont the gear grab? this is the first time ive had this problem with a manual transmission...

 

[FORDMAN41291]

also forgot to ad that i block the truck off with bricks when im on a steep incline..

 

[IH POWER]

Im not sure but my 6.9IDI will slowly roll back on a steep incline and its because it has low compression.