I would load test them. The digital battery testers are not always accurate. I have both and got different results. A load test will tell you if the batteries are good under a load.
May be I missed it but have you checked both the batteries to ensure they are both good? When I say checked the batteries, I don't mean with a volt meter. You need to load test the battery's.
I think you would have to. With out the spindles I don't think it would make sense to even buy the lift. I don't thing it will lift the truck without them.
If you are going to stick with 33's and want the lowest lift possible, I would to the Cognito 4inch lift and drop it as much as you can...
Here is a picture from a couple years ago. Cognito tapered 2 inch blocks in the back with Sulastic shackles. the front raised to match the rear. I believe it is a 1/4 to 1/2 higher in the front. I don't like the look of the front end down at all. Running 35's on 17x 8.5 Methods with 0 offset...
This is with 1 inch blocks in the back and I believe the bolts are turned down but not out to the lowest position. Wheels are 17x8 I forgot the backspacing. Tires are 285/70/17.