Ah yes HGB,
I remember that weekend as well. I was in Indy all weekend. Mario was caught in a somewhat tricky situation as the Zolder GP and the first weekend of qualifying for the Indy 500 were the same weekend. Mario originally was going to try and Concorde it back and forth, qualify at Zolder then scramble to Indy, qualify his Penske then jet back to Zolder for the race. In the end he decided to bag that idea and Penske Racing had Mike Hiss qualify the car for him and Mario just stayed in Belgium. Good thing he did too, it was the race debut for Black Beauty and he led from pole, never pressed and won flag to flag. Storming drive that day by Peterson as well.
John