Hello friends, I need a new set of motors for my 90 Grady 28 Marlin. I see a gentleman in Fords NJ has a set of HPDI 250s I been eyeing up. I am very new at the repowering game, I tried going at it last year, taking a gentlemans words on a set of OX 66 250s, and bought a bad motor, so Im a little timid about making the same mistake twice. What do I need to do to ensure I get a good set of used motors. Thanks Glen