[Dick Butler]

Well I can answer honestly fearing despite the fact I fear that the wording of the questions points to you thinking I think only one car should be legal for GT/AA or other GT classes.
I ran 454/425 hp at 3610 lb. My best winning time for class was 9.51 when all the cars were basically the same motors or the 454 oval port motors which ran very similar et.
This was class winning time my last year at Indy. This car could still race class but without much chance of winning.

454 low compression truck motor which was able to run 8.60s to 70s. That makes it seem bogus in factoring. Someone else might remember the hp rating. Smart find by the builder but points out the fallacy of using HP for classification in the long run.

I say no to a single combo in GT/AA question since that is not current rules but .... Might be helpful to make it so the racing does not involve another 30K motor every year and complete changes of combination to be able to compete.

25GT classes -Same answer.... Not current rules.....

Wild equipment and machining--- Honda rod bearings, oversided cams. Ported Heads and manifolds. Exotic materials....

Many successful racers love things the way they are. That is fine. I believe the rules should be simplified for ONE or two classes for growth of class racing. Aging racers points to need for entry level for new people who might not have parents currently involved.