I'm not sure what the rules allow, but I kind’a wondered about the tyers. Why go to the trouble of replacing the engine to find that extra speed, and then use period tyers? Makes me think that there might be an alternate reason for replacing the engine. Should we condemn so quickly?
Also, I didn't attend the Saturday meet (Sat weather was fine and sunny), but I did notice that the GT40 had started in front of the Lola on the grid. I wonder if that meant that the GT40 was quicker in the dry?
Incidentally J6, I totally agree about the slippery-slope. When I was racing old Triumphs, I ran many a campaign to, at least, allow a CATEGORY of ORIGINAL race cars. It was always an uphill battle.