If he claims six by eight (six long, eight "wide" or perhaps in circumference), you're getting into choad territory. See choad also spelled chode. Demand immediate proof.
"So he told me, 'I've got an eight by six.' At first I thought he was talking about a new kind of car engine, or something. I finally figured out what he meant, but he had already proven himself to be such a jerk that I had no desire to check out that particular attribute."
Old Joke -- Q: What's a Gay Eight? A: Six inches.