Though a little painful this go round considering you mentioned you don't have a hoist, but why not remove the bellhousing and replace it with a stock GM truck bell with the open bottom so you don't have to a) go thru this again every time you replace the clutch and/or b) hack up the original mounts? They work fine without an original bell housing and no rear trans support is required. Old bellhousings are a dime a dozen - but you would need to ensure you grab one with the correct index ring diameter (or also buy an index ring adapter, additional cost - but since you'd be shopping, you can choose wisely 1st time out). Just a thought.
Glad you are getting around to this upgrade, you'll be very happy with it - it's been a while since I posted
this thread, but sharing in case you might learn from some of my mistakes!