Tom, the car in foreground is Mickey Thompson’s driven by Jack Chrisman. It was powered by 2 BOP 215 cu.in. aluminum engines from the ‘61-‘63 midsize Tempest/F-85/Skylark.( I think 1 Pontiac and 1 Buick) The blocks were similar but the heads were different. The Buick version later became the Rover V-8.( as well as the basis for a M/T Indy car and Jack Brabham’s Repco F-1 winner.)
Sorry RRR, I don’t mean to step all over your build thread, but I’m a little OCD over this era of diggers.