I would say it depends on if you can determine if he filled out the card himself and was not dictating it to a person at the draft board. The sound of five and nine are similar that is why in radio communications one says "niner" to make sure 9 is understood clearly. Also are you looking at the scanned or microfilmed image of card or a transcription?
He could have been trying to be "older" in the belief being over 30 would be less likely to be drafted.
A four year difference is not bad as records that old go so use the one claimed at death or use the one you have the most records of it being. Or I would just use 1885/89 in my databases.
P.S. If still an "alien" then could not be drafted but could volunteer.