Convert table from MyISAM to InnoDB and keep MyISAM rows order
@a_vlad has your answer... create a new table with the same structure without keys and autoincrement (it is faster to manage indexes in batch than one row at a time).  Then insert into the new table select * from the old.  After population, any indexes (including the pk) can be applied and add autoincrementation advanced to the next value you want to generate.