level with me all the way -??

(source: Iceberg Slim- Pimp, The story of my life)

The section of the novel that contains the expression:

”That cocaine had her speed rapping. I couldn't cop her tonight unless I croaked Scarface. My plans had to change. I had to unhook her from Leroy soon. She'd make bales of scratch. Maybe I could work an angle to get her and a slice of that settlement. Of course, I couldn't wait forever. If I had to, I'd cop without a slice of the settlement.
I knew Leroy was going to blow her. He didn't have a chance to hold much longer with that ugly face and that jealous bit. I had to find out if she would level with me all the way. Silas had told me she was an ex-whore.”

Background:

Slim tries to convince an ex-prostitue to get back in the business and be his whore. He gives her cocaine and amkes her telling him her whole life. Slim realizes as the main problem that the girl is married, however his husband has a distorted face due to an accident and a jealousy mania. He considers also important if the girl ’would level with him all the way’

Could someone explain me what Slim does mean by that?

If she levels with him all the way, she is completely honest and open, hiding nothing.