The problem with this kind of spot is that you have a worse hand than villain is afraid you have. So you're raising for value here with A9 when villain thinks you have 5x (albeit.. they are pretty much the same thing here).

I think a smaller raise could be ok, and probably get more stubborn calls from AK/AQ type stuff. Maybe make it 56 or something.

But by all means if he's gonna think "zomg he missed his spades" then a shove is good. Depends on villain ofc.