My 347 is pushing 10,000 miles after 3 years.
No issues. Being a weekend car, by the time I hit 50,000 miles I will be wanting a new combo anyways, lol
Let's face it, the 331/347 has only become popular (affordable) in the last 4 years or so, and with the initial 347s came some problems as any NEW concept would.
Most 331/347 either haven't been around long enough to really have accumulated any real miles like 200,000. Most people that are building them have second and third vehicles that are used as daily drivers, and the 331/347 are being driven HARD, but only as occasional drivers, so real milage accumulation isn't something there either.
Plus with the emission laws out today, in many states, it is hard to get away with the larger then factory cubes.
So the long and short of it, IMHO, is that you will be hard pressed to get answer out many because they just havent' been around that long.
good luck, I luv my 331 because I still can run the longer 5.4 rods compared to the 5.315 varity of 347, but this is my preference.
If it LONGEVITY you are after, stick with well built 302/306, they have proven to last the test of time!
I have ~10k on my 331 over the past few yrs, its nothing too wild tho. I too dont see putting much more than this on a combo before im bored and want to go a diff route tho...
Good post 06cobra I was starting to think I should've titled this thread "anyone got a stroker broken in?"
Seriously, thanks for all the responses.
I thought strokers had been around considerably longer (they say the mind is first to go). Just kicking around the pros and cons of a 331 or 351. I have conserns about the rod ratio on a 347. Hoping this would prove me wrong. Longevity is just one of many factors. All my cars are driven/beaten at least 7,000 mi a year. Whatever goes into my 68 has to last me more than 3 years (barring an under-hood explosion). A 351 opens a whole bunch of other issues.