Brothers 98 GT 4.6L broke a timing chain, and he was told that's likely to have resulted in piston damage. My dad wants to swap in a new 4.6L. I have a few questions. Few questions: 1) Is it true that a messed up timing chain will have likely resulted in internal component failure? I'm not sure on the exact driving 'symptoms', I'll have to add those once my dad responds. He has a service manual that says "broken timing chain = likely damaged internals" which is what he's basing this on. 2) Are there any components that support a PI 4.6L that are different from a non-PI one? Here I"m thinking of things that normally wouldn't come with a new engine... the transmission bolthousing, exhaust manifolds, mounts, whatever. 3) Are there any components on a PI 4.6L that my dad/brother should be sure come with the motor because the existing NPI equipment won't work? Google suggested the Mass Air Flow unit would be different. ANything else? 4) What should he expect to pay for a 4.6L? I would think for either PI or NPI it' dbe in the $500 range for a used but running unit, and I wouldn't imagine much of a price difference these days between the two. 5) Are there any advantages to the PI motor besides the extra 50 horses? My dad is mostly concerned with just getting the thing running, whereas I would never let an opportunity like this to swap in some power go by. It'd be easier to convince him to make the swap to the PI if it would be likely to prove more reliable (any internal components stronger) or maybe even help him pass California smog a little easier. THanks for the help!