I think the issue with the gripper when translating large objects is that it "animates" the movement as you drag so it has to recalculate A LOT. Something that I often do is select the object, the gripper appears then instead of clicking and dragging the particular arrow for the movement you want to make, just click the arrow and release. this will show the data entry box that you can then type in the exact distance you want to move it. The object won't drag across the screen, instead it will just appear at the spot.

Also, If you are moving it to a snap location like aligning it with another object, you can use the translate tool from the tool pallet or from the menu bar under Modify-->Transform-->Translate then you just select the large object you want to move, select a start reference point and an end reference point. It will give your machine time to calculate the move.

Check out the tools under Modify-->Advanced Transform-->Assembly

There will be a smaller toolbar that open which contains the tools Connection, Mate Faces, Align Faces, and Insert Face

Depending on what exactly you are wanting to do, one of those should be what you're looking for. There is a relatively good description of how each tool works in the user manual. All of these tools are associative so the two objects that you align will follow each other around if you move them.

If you just want to line up the cylinder head to the block, you can translate it again with more precision if you zoom in and use the translate tool again, but this time select a point that the two will have in common once aligned. You'll need to have snaps enabled for this to work right. For example, if it was two squares, you would click the corner of one square as the start reference point, and then click the corresponding corner of the other square. This would have the side effect of aligning those faces as well. If there are bolt holes in the head and block, you can use the center point of a hole to line them up so long as you have center snaps enabled from the snaps window.