The bases that are bolted on right now look like this...
I have a set of used "tall" universal mounts (~3" taller) that I could swap over to.
I also have set of Eseries driver/passenger seat adapters (non-swivel type) left over from another project. Those would be $595 extra. (they look like this...)
I don't make the Sienna bases any more, this is all just stuff I have left over in the shop. I actually have two pairs of seats to sell but I'm currently using one pair until my new Scheel-Mann seats show up.