You will find you get VERY biased 6.5L info here. The 6.5 bashing here is worse than most FORD forums I've been on. Yes you can chip it, but I would save your money and do other mods 1st. Do things like upgrade the cooling system to the balanced spin on fan clutch water pump, make sure all the cooling system is up to par, put an exhaust on it and get teh EGT's down, find a K47 airbox to let it breathe better, reloacte the PMD/FSD out of the engine bay and get a spare to carry in the glovebox, better lift pump like the 93 style, and all the other general maintence. Before I would even CONSIDER chipping one, I would replace the stock turbo with either an A TEAM TURBO, or even one of the HX based HOLSET's. The stock turbo is a killer of these engines. They run WAY to much backpressure on the exhaust skyrocketing EGT's, not to mention choking the intake off. MANY peopel out there chipping high milage 6.5's, and having them live just fine, but you MUST do the supporting mods FIRST! THEN THINK about chipping it.