I would agree that claiming an engine may make your name Mudd but if there is one guy who it is obvious that he has an engine that has no business being in an Enduro then.......
Wouldn't a better rule just be a compression limit? I would think that the track wouldn't want to spend a lot of time teching Enduros so wouldn't this be something that could be checked before and after fairly easily? Check all cars before the race and the top 10 after. If your compression is above what is allowed DQ.

Compression can be dropped with cam timing, and leakdown lifters. Lobe separation can drop it, and so can advancing cam gear 4'.... but doesn't effect dynamic compression above 3000 RPM. so if you have 11-1 compression, with these two tricks you can drop it with the plugs out to 9.75. Even a 9:1 compression motor with the right heads can make 300 horse easily. I feel the class is fine the way it is. Competitors will always find a way to make the power up, and always have. Weight, tires maybe gears will curb it a bit. I understand everyone wants the faster guys to slow down, I say catch them. You can make a good running engine cheap, just research and buy your parts.

The parts for a good rebuild kit (if you know someone isn't more then 750 for the entire kit. Camshaft with lifters on the high side is 300. Rochester carb that flows 750 or more is like 250 new, is rarely screws up. A set of weights for your distributor, and a good MSD module (HEI) is around 70 total [which is worth 15 horses alone... and reliable]. There are 1.6 stamped rockers out there, that grab you 15-30 horse depending on what cam you have. Stock GM pulleys, that slow down the water pump and alt.. theres 15 more.

At the nationals this year the top 2 or 3 cars where checked for compression ratio. Most enduro cars I have seen checked are usually around the 9.1 ratio.

how about if they made the enduros run a msd box with a chip that ran up to 5500 rpm so that everyone is running the same rpm that would bring the feild alot more closer

We aren't street stock, I run this class because of the fun factor. I prefer if they leave the class alone. Even with my slight budget, I have fun out there.