No.
If you ever opened a 1U case you'd know. A rack case is 425mm wide, why would you want to put a card on top of the CPU if there's room to the right. 1U Rack cases usually have right hand riser for a single card, so the card covers all the slots of an ATX mainboard.
Mainboard standoffs are 5mm, add 2mm for the PCB, 7mm for CPU socket CPU and heatspreader, that's 15mm. Inside the case there's 41mm room, guess how tall passive 1U heatsinks are: 26mm. There's just no room in a 1U case above the CPU area.
The HST1155LP is a special heatsink, but it still adds at least 8mm height. That leaves you with 18mm at best. even if you can cram the card in, there's no room for the back connectors, because the mainbord's connector will get in the way of the tall sockets on the
[email protected] card.
It
might be doable in a 1.3U case. Why would you want to use a rack case in the first place (unless it goes in a rack) ?