What is the expected engine life for a 4.6 2 valve and 4.6 4 valve? I know to give a perfect answer much more information is needed. However I'm looking for a general answer. I'm looking a few Mustangs to hold me over till I can order a new one, everything from an 01 Bullitt to both a 99 Cobra and 98 Cobra. The last V8 I had was an LS1 which were known to hit 200k miles with proper maintenance. I have only had one mod V8 and didn't have it long enough to get a feel for what the motor was capable of in terms of longevity. All help would be appreciated!