i recently purchased a 25 or so yr old pattern plane with the engine screwed to maple (i assume) rails. the 4 screws were so tight it literally took me 2 days to remove the screws. i would push extremely hard and twist, i could just barely twist the screw. i had to do this the entire length of all 4 screws. i was worried about stripping the head. my hand would get so tired i had to come back later. i would say, based upon that experience, that maple rails would do just fine.

david