It's probably 1/2" too high based on your information. I wouldn't change a thing for 1/2"
Run with it for a few runs, and see how it goes. Err on the high side, adjust from there. I think you've done that.
To your turnbuckle question....
You state, torklift springloads....does that mean the basic ones?
Do they look like this?:
Here's instructions for those:
basic torklift turnbuckle instruction video300 inch lbs it sounds....
Try www.torklift.com for specific instructions on all their different types of turnbuckles.