Track rules today vs 1970s  

I do not race today but I see all the track tire rules Track motors sail or no sails and God knows what else

In 1974 When Alfrey 47 Modified was on the track we went any where and raced Weight  rule yes But i remember us using any tires we thought worked that day I think ther were some motor sizes  

But to my POINT how are they controling the cost when you have to have a different car motor and tires for each track  

John Mc,  you were in tech can yon answer any of these questions