With 24 x 10 +30 on 295/35R24's I would do a 2/3 drop and call it good. That 295/35R24 is as close to an overall tire diameter to a 285/45R22 as you can get for a 24" wheel; Which would be the OEM tire size on GMT900's optioned with 22" wheels.
I tried to find a thread like the "Show off your 2015-2020 lowered tahoes and yukons" but for the '07-'14 GMT900s and there doesn't seem to be one in the Street Suspension sub forum or I didn't search enough. But this will give you some pretty close visual ideas:
https://www.tahoeyukonforum.com/threads/show-off-your-2015-2020-lowered-tahoes-and-yukons.92185/
I know mine wasn't a GMT900, but here's the thread to my '15 Yukon XL Denali dropped on 24's / 305/35R24:
2015 Yukon Denali XL Exterior is finally done so I figured I'd create a thread and post some pics of how it sits currently and a bit on the process to complete the mods. All chrome has been deleted with either OEM parts painted to match, replaced with OEM Gloss Black trim pieces, or OEM parts...
www.tahoeyukonforum.com
If you have any rubbing at all it'll be at full lock and it'll happen right on the rear side of the front wheel well. With a 295/35R24 and +30 offset you may not rub at all. I had 24" x 10" +28 305/35R24's and only had minimal rubbing at full lock on the back side of the front wheel well. Over time I did wear a hole through my factory fender liners and then ended up replacing the fender liners and doing what's referred to as the "Norcal Mod".
Here's a video of the "Norcal Mod" I'm referring to; The process is the same on the GMT900 platform and if your tires rub at all it'll be in this same spot referred to in this video:
Personally, I much prefer the idea of drop spindles in the front. Because spindles don't have an affect on the length or pre-loading on the factory strut and spring; Therefore the ride quality remains the same as stock. However, it's been reported by some owners that some drop spindles can impact turning radius, as in making it so your vehicle doesn't turn quite as tight of a radius. If so it's very minimal and you'll only notice it in parking lots pulling into tight spots. You likely won't notice it at all since you have a Tahoe and not a Suburban/XL/ESV.
Not all drop spindles are created equal. Depending on your OEM suspension, how old your springs are, etc. You may or may not get a full 2" drop from front drop spindles. But that's also ok because if you only got 1-1/2"-1-3/4" drop out of some front 2" drop spindles then that still falls within range of your target front drop of 1"-2".
What's the exact year and model trim of your Tahoe?
Do you know what factory RPO suspension code you have?
Providing the exact year, model trim, and RPO suspension code you have will help others provide some insight on what type of lowering kit/parts to use.
