I've been watching the original ABC coverage of the 500 during the 70s on YouTube, one race after another. I was at the races from 1975 on, so the memories are fantastic. Especially considering I haven't seen these telecasts since they originally aired on Sunday nights after I got home (and I was operating on no sleep for 36 hours plus).
I'm trying to remember what it was that caused Al Unser to leave Jim Hall's team. He wins the 500 with the brand new team in '78 with a Lola. Then he dominates Indy in '79 with the new Chaparral before a mechanical failure. Then he's gone after the season. For Longhorn of all teams!
Why did he leave?
Another note: For people who believe Al wasn't a charger and that he waited for races to come to him, just watch '77, '78 and '79. In 77 I accurately predicted he would lead the first lap ahead of Sneva and Foyt. That's exactly what he did and ran away from the field. His battle with hot-foot Danny Ongais in '78 for 75 laps is a classic. Same prediction in '79 from the same outside position. He jumped ahead of Tom Sneva and Rick Mears and ran away from the field.