If you remove the radiator, fan, pulleys, etc etc off the front first you can slide it forward enought to clear the input shaft. To get to the top bellhousing mounts easily lower the gearbox down until the rocker cover almost touches the firewall first. Take the top bolts out then raise it back up bolt the gbox crossmember back on.
I reckon the easiest way to get at the top bellhousing bolts, is once you have all the "peripherals" outa the way, attach the sling, undo the engine mounting bolts / nuts, raise the engine enough to remove the mounts, then lower it back down onto the mounting brackets...
This will give you enough room to get at the bellhousing bolts without having to touch the g'box crossmember
Don't forget to support the front of the g'box as ya slide the engine forward