Possibly looking at an 08 D7 with a bad crank seal and need some advice. Sled has 3000+ miles with 300 on top end. Has Boondocker NOS, Skins hood and other extras. Owner says it idles and runs and the seal went out end of last season. What should I look for? He's asking $2500 but if I can get it for less I think it would be worth it. Any thoughts? THANKS!