Hi RedArrow9,
First off, a 740/Q49 is an outstanding Score, so you can comfortably apply to any PhD Programs that interest you. By extension, a retest is likely NOT necessary.
The PhD application process tends to be a bit more 'rigorous' than the MBA application process is - since there tends to be a small group of highly qualified applicants competing for a relatively small number of PhD 'slots.' As such, beyond having a strong GMAT Score, you'll need a strong OVERALL profile and you'll need to properly 'market yourself' to each individual Program that you apply to. By extension, you would likely find it beneficial to speak with an Admissions Expert about your overall profile and plans. There's a Forum full of those Experts here:
https://gmatclub.com/forum/ask-admissio ... tants-124/GMAT assassins aren't born, they're made,
Rich