Huh, saw two of those at the recent Portland Chump Car race. The team swapped two blocks in the span of the weekend. The third one developed a huge coolant leak, so they parked it for most of the race and limped it around for the last 15 minutes.
It was interesting watching them carry the blocks through the outside paddock, over the foot bridge and down to their pits. I have a hard enough time carrying a mountain bike up and down that foot bridge....
The first time they swapped the blocks, there was a team across the aisle from them swapping the 5.0 in their Thunderbird (twisted the oil pump drive, they were the 2nd Ford V8 to do that at that race). They both finished their swaps within minutes of each other and were back out on the track.