Josh Brolin has proven to be a good actor and I think he could do justice to a Heflin role. In his later years, Heflin became really craggy, almost weather-beaten; that aspect of his I think would be hard to duplicate today - he didn't age well but it was of no matter since he didn't rely on his looks.
In what proved to be his last interview, early 1971, Heflin said he planned never to retire. It's too bad he didn't live longer; he was getting ready to appear in a Western (don't know which) at the time of his death.
"Life is a scam"

• Steve McQueen

He did do pretty well in Yuma. That remake seemed to have an entirely different feeling or tone than the original and I just couldn't get into it. I'm not sure that a great western has been made since Unforgiven.
What do you think about Josh Brolin in a Van Heflin role?

I agree with you; I can't picture anyone playing a Heflin role better than he did. Christian Bale did a decent job in Heflin's role in "3:10 to Yuma" but Heflin was better.
"Life is a scam"

• Steve McQueen