Al Sr. was one of the very best. I saw him race at Laguna Seca in F5000 in the early '70s. F5000 was a great series, faster than F1 at the time. I always considered Al an oval guy, but boy was I mistaken. He hustled that F5000 car around Laguna like a gifted road racer. Mario was his teammate. IIRC they finished 1-2, and at the time F5000 was jam packed with talent.
On a closely related note, read Al Unser Jr's latest book. Shocking is an understatement!
RIP Al.
Scott