[ALMACK]

One other thing I do not think was mentioned yet, is that by attempting records at 1/4 mile National Opens, the racer can set both 1/8th mile and 1/4 mile records at the same time.

If you attempt a record at a division 1/4 mile event, you can only go for the 1/4 records...IIRC.

As posted above: If a racer attempts at a Divisional race there is the risk of getting a h.p. hit the following Monday, so that's one of the reasons why National Opens are more favorable for record setters.