Alright well let me expand on mine. Mine was tappping for a while but it didn't seem like bottom end it sounded like something to do with the timing chain clacking around. I put an h.o vortech kit on the car with cams and longtubes and all and honestly if i hadnt had the preexisting rod bearing issues it would be fine but you are much better off keeping yourself around 475 its kind of a safe in between. Plus it really all depends how you drive it and if you race it. One of our members mick is kicking 528 to the wheels someone correct me if I'm wrong. Out of his saleen charged GT and hasn't had an issue yet.
Not sure my info is valid, but here goes: ( 2011 Shelby GT 500 )
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Stock it dyno'd @ 481.4 hp / 476.7 tq...............did a blower upgrade on 29 April 2011, ( FRPP part # M-6066-MSVT29D, 750 hp ) kit consisted of:
2.9 Whipple blower, 123 mm MAF housing & zip tube, twin 65 mm TB, FRPP upgraded duel fuel pump, FRPP Pro Cal tune..
Car now makes 656.17 hp / 594.81 tq...@ 6000 rpm.....if you look @ the Shelby site, this is pretty much what you get in their 30 K Super Snake pkg. - all the visual upgrades....it's based on a stock motor !! ( haven't seen many threads on Super Snakes blowing up lately )
Having said that, if you're looking to rev your motor to 6300 rpm + better build the bottom end !!!
i've got approx 420 at the rear tires, i made 454 with 2 more lbs of boost but i stepped it down a pulley. So at approx 420/420 i've put down 15,000 and climbing daily driven miles on my car. No issues other then a tune issue i had with my dyno tune (unreleated to blower/engine install), and my TB spring popped outta place on me once while made me jump into limp mode.
I fire it up everyday and drive it around. I don't beat on my car, everyone knows that, but by myself i do open her up and get to the 5,000 rpm range so its not a completely babied car. The trick to that much power it two things, your tune, and your RPM's. Keep both of them in check and at reasonable levels and you should last a while.
well yeah if you can keep your car under 5k it will probably last forever... but now returning to reality its really all about your tune but seriously at 500 your pretty much on borrowed time.