First, let me give Popular Library's Hardman series my highest recommendation.
In all honesty, Ralph Dennis' adventures of unlicensed P.I. Jim Hardman and his black sidekick Hump Evans don't really belong in the "men's adventure" genre. All twelve books are more like detective novels than slam-bang sleaze and action. Hardman has been compared to Spenser and Rockford, and I would go along with that.
However, because Popular Library packaged them as men's adventure, including numbering the titles and giving them violent painted covers, I'll cover them as such here. But whichever genre you like better, you should definitely seek out the Hardman books.
They were written by Atlanta-based author Ralph Dennis in the 1970s. Instead of getting into Dennis' bio, I'll send you to mystery writer Richard A. Moore's excellent article on him.
As for 1974's DOWN AMONG THE JOCKS, the fifth Hardman novel, well, it's pretty darn great. It begins with Hardman and Evans viewing an 8mm film Hump received anonymously in the mail. It features one of Hump's former NFL teammates, a real asshole named Ed Cross, in bed with two women. That same night, Cross is found beaten to death, and the prime suspects are Hump and four other guys who received the same film. The theory is that Cross sent the film to men whose girlfriends or daughters he had slept with as a "screw you." That's the kind of guy Ed Cross was.
With Atlanta cop Rex Martin targeting the 6-foot-7 Hump for murder, Hardman, a middle-aged, pudgy dude whose hobbies are limited to drinking and grilling meat, works with his friend to clear Evans' name and find the real killer. What's interesting about the novel and the seamy underground its characters are so comfortable in is that the reader is never entirely certain Hump is innocent. Even his best friend, Hardman, concedes it's possible he could have killed Cross.