General Support: Large thumbnail size.

Is it possible to have more that one width constraint for the large tumbnails? I have a HUGE gallery of my wedding images, and some are vertical and some are horizontal. I like the horizontal ones to have a width of 650, but the vertical ones to have a height of only 650 so they arent too long for the page, so the width is obviosly smaller than 650. I did all the scaling myself and put the images in the thumbs folder. I changed the size in the options, but it will only display the horizontal thumbs since they are the ones that are 650, but it wont display the vertical ones. Can I remove this and just have it display whatever size the thumb is nomatter what the width is? Thanks.