How is he ranking with GSA blast ?

While checking one of my competitor I found that mostly his backlink profile consists of GSA blast or some other maybe. He is ranking at 7 for some cpa keywords.
And when I ran his site with MOZ found that he had a pa of 34 and Da of 52.

So, the question is can we ranked with GSA blast ?

Yes, Still possible to rank with GSA.

Your link list must be a good one. Also, you will need to squeeze that link, for every last drop of links that you can get out of it, and that means using good email accounts, good captcha solving, etc. I am seeing a drop in the number of buildable links, but when squeezing the list, it should give you the extra push.
Also, I think there are other factors as well, such as using expired domains, 301 links, etc when ranking - try checking for those as well.