My wife would like a tahoe or suburban and I am trying to weigh the pros and cons of a 350 or a 5.3L in a newer one vs an older Burb with a 6.5L. I have a line on one that is a '97 with a full load leather 4x4 etc. What kind of milege can I expect vs the gassers and also what are the operating costs of a 6.5L like. Like my dmax needs a fuel filter every 20K at 40 bucks. At how many miles should I forget about a used 6.5L or are they worth refurbishing. I wouldn't be doing the work ourselves. Any information on this would be great.