What are all the classes 914s race in?, Past and present. Options

[Mark Henry]

IMSA thread has me wondering. Does anyone want to take a stab at the list and a brief explanation on what's legal (stock, mods, engines, tires, etc) for each class.
Whenever I've built a race engine I just asked what pertained to the engine I was building and honestly I've never looked any further. For anyone thinking of going down this rabbit hole it might be nice to know the differences.

[brant]

The problem with answering this question is that there were small changes over the years in the rules

Then in about the 70’s New sanctioning bodies (with new rules) started to form

By the time PCA became a racing sanctioning body in the late 80’s there were over 50 vintage clubs that were also sanctioning bodies

So a current explanation of where a 914 can run involves 50 different (although with lots of overlap) sets of rules

This is the reason vintage racing is frozen to a point in time
And the major philosophical difference between the FIA and say a vintage club

The fia changed rules every year and marketed towards manufactures. After a new car debuted it was uncompetitive after 3-4 years because the rules had progressed and the car hadn’t The FIA facilitated this and would drop cars from eligibility... effectively

Your question should be about an era or specific sanctioning body to get a specific answer.

For example I could say that a fast 914 race car ran with a large v8 in lemons or nasa
But not as any manufacturer ever intended. More as an individual dream or vision was developed by one guy. Nothing wrong with that but I think your asking about air cooled motors.

This the reason most vintage cars define rules in periods such as 1967, 1972, 1981. Or periods from different sanctioning bodies such as the scca. The FIA or IMSA