David,
First, I am not trying to beat a dead horse, but I STRONGLY suggest you call Robin Carriger (817) 300-1132 and get yourself a copy of his Wholesaling Home Study course. This kind of question (and TONS of others) is covered in it VERY WELL.
Second, I am not a lawyer and am NOT giving you legal or any other kind of professional advice. For that you might try contacting an attorney, doctor, CPA, etc.
Third, I believe the answer to your question is, it depends on how you do it and who is working the other side of the deal.
The last time I worked one, HUD expressly prohibited assignments of contracts by the Buyer ("John Smith, and/or assigns"). That said, sometimes you can sneak in a "Marketing Fee," although it appears this tactic is becoming MUCH harder to do.
Another way to accomplish the same goal (wholesaling thru assignment) is by taking the deal down in a corporation as the Buyer's name (i.e. "REIMENTOR, LLC"), then, rather than assigning the contract, you sell the stock in the company at closing.
In this scenario, REIMENTOR, LLC would still be the company buying the HUD property, however, the person who put it under contract (i.e. "David Acuna" - old REIMENTOR, LLC owner) would be different than the person who owns the company at closing, and thus the one buying the property (i.e. Greg Wilson, REIMENTOR, LLC new owner).
You get "paid" for wholesaling the deal by setting the company up for about $310+/-, then selling your stock in the company for your "wholesaling fee" - say $3,000 + $310. You accomplish the same thing as assigning a deal and still manage to stay HUD-compliant.
If I can help you with your real estate investing needs, don't hesitate to call me at (817) 230-4800.
-Greg Wilson ("The REI Mentor" - www.reimentor.com)