Anyone know how much more it extends than stock? Can't seem to find the dimensions anywhere.

Doesn't it say on their website?

Nope

Alright, let's rephrase this question a bit - which are longer: rubicon express extended bumpstops or daystar extended bumpstops?

I would rather they be too long an have to trim than be too short.

Found the info, here it is in case someone stumbles upon this thread and needs a quick answer:

RE's are extended 1.5"
Daystar's are extended 2"