Now wait a minute guys the 53 block was not limited to the just the 99s:-laf - do a search here and you see them on 01s as well. Regardless, any one familiar with a 53 block will know where to look to see if it has a 53 or not.
transmission's definitely the weak link on a sale. $6500 seems about right, I'd keep it and do the trans before I took a penny less - did anyone miss "rust free"? That's got to be good for something.