'West Texas' millionaires only invest in entrepreneurs who have this trait

What's more important than a good idea?: Millionaire CEO

Wayne "Butch" Gilliam and Michael "Rooster" McConaughey, the self-made millionaires who co-star on CNBC's reality pitch show "West Texas Investors Club", won't do business with just anyone.

The pair, who previously shared a story of being ripped off from a business deal gone wrong, said they only invest in entrepreneurs who have integrity.

"You can have the greatest idea in the world and have somebody that doesn't have any integrity running it. How's it going to work?" McConaughey said. "It's not going to work."

Wayne "Butch" Gilliam and Michael "Rooster" McConaughey from CNBC's West Texas Investors Club.

"We don't want to have to worry about whether that person is capable or whether that person's got integrity [or] whether that person's honest," McConaughey added. "Not everybody is good at everything, but if you do have integrity, you are worth helping."

Having street smarts and a strong work ethic paid off for them.

Gilliam is a mechanist who became a millionaire after selling the intellectual property for a unique pipe threading technology. McConaughey is a self-titled "junker" who built a lead pipe empire worth millions. They are now co-chairmen of the venture capital firm West Texas Ltd.

"Invest in yourself, make the right decisions and be honest," Gilliam said. "And there should be a pay day for that."

CNBC's "West Texas Investors Club" airs Tuesday at 10 p.m. EDT.