How are today’s as/ah cars different

Also, the cars are lowered a bit which helps with aerodynamics a lot.
Rear suspension and tire technology has come a long way since 1968.
Cams are physically bigger and have needle bearings instead of regular babbit cam bearings that reduce flex and friction rolling resistance.
Head and intake technology is way further advanced.
More accurate machining in the engines as well as more accurate balancing.
Add it all up with rule changes compared to the past as well as 50 plus years of R&D, these cars are more expensive to build to be competitive, and last a lot longer when built.
The cars as produced in 1968 were very crudely built and were intended to be a starting point for racers to build and make safe and competitive.
They were not ready to race at all when picked up at Hurst or dealerships, contrary to what some people may think.......