Late model Pig hoods can be extremely hard to find in nice shape - they are weak and tend to dent. I have noticed the glue bonding of the braces to the hood sheet metal can pop loose, too - I reglued mine with a urethane adhesive (PL-series from Home Depot).
The claim is that the late model hoods have the 'power bulge' for the 2F air cleaner. I have seen early hoods put on pigs with late style 2F engines, and the engine still cleared the 2F air cleaner.
I like to use the term 'power bulge' just because it should be worthy of guffaws and outright horse-laughs among those who know the output of a 2F.