Welcome to the forum CJ make sure its am original 4.2 it may be a converted blown up 3ltr.
As Growler says history is everything, without it you are buying blind, CRD are a good buy
expect about 12-13 lt /100k the 4.2TD may be 15ish per 100k.
Look forward to pics of what you buy and why, jump in and ask away You'll always get an answer