It's no guarantee but it's a good place to start.

Don't waste time doing what your competitors are doing, sign up for my course and I 100% guarantee you won't make a dime! 

The loan also contained a substitution of guarantee clause, as long as the substitute guarantor had a met a minimum credit score, which the builder/investor did.

the point i was making was not "if you buy real estate you're guaranteed a gnarly turnover," it was more what @V.G Jason stated - if you live in California and buy something random in Ohio that you've never seen, you're going to have trouble. 

On the other end pretty much all mortgages on a corporation require personal guarantee which is full recourse

I’m looking for guaranteed income using Section 8.

Vacancy is costly and while there is no way to guarantee one tenant is going to stay longer than another, talking to people and learning a little about their life and situation should give you some clues as to how long they might stay in your place.The probability of you getting a home-run tenant right off the bat is pretty low. 

It also takes a personal guarantee from the borrower.  

Because I I have this new deal that’s GUARANTEED 17% IRR.

As severance he has a guaranteed salary plus $2000 housing allowance for three years.