+1 Flat6pac
1/4 Ton Capacity Hydraulic Lift Table
I have two of the larger (1000lb.) version of this, they are absolutely indispensable to me. One engine on a cart, load up and change out another one without ever tweaking my back...
I got the larger ones for about $200 each w/ coupon...if you look for a coupon online you can probably get the one above (500lb.) for $150 all-in...
I used to use the cranes but they fell out of favor to me because the width between the legs was annoyingly narrow and the engine swung around too much, and was usually off-kilter at a bad angle.
ymmv