There's not a lot different between 2764/2732, only some extra address or chip-select pins.
These can all be tied to Ground to act like a 2732 etc...

From memory, i *THINK* the 25xx series may use a +12v supply as well as +5v?....obviously you wouldnt connect 12V anywhere on the 2764....

One fantastic bonus is that you could squeeze 2 of the 2732 (or 4 of the 2716) game-roms into a 2764, then use an external switch to change your pin between 1 of 4 different gameplays.

No doubt you would also be upgrading a few other roms too.

This would be handy if you had a few different playfields for the 1 cabinet and simply enabled a different rom section for each different playfield....

Oh yeh, if you're into hacking the roms to modify gameplay (e.g. scores, multiball, bonuses etc) you could switch between the original and modified speedily too, instead of plugging the roms all the time, while testing your mods.

MM.