i did the same damn thing on my rear mount setup a year ago... coming back (winter in mt) -20 or more outside, pulling big hill started to really really go hard thought man this cool air is doing wonders looked at boost gauge it was pegged... bout **** but havent had any issues since then.

 

UPDATE....got an '06 5.3 swapped in, and it's running great considering it's the same baseline tune blackbear sent me for the 4.8. I put a 7psi spring in and at WOT I'm seeing 8psi on the gauge, full boost by 3000rpm. I haven't flogged it too hard because it seems to be running lean by the AEM wideband, but when I did hit it on the highway it laid rubber at 70mph. However I'm seeing AFR's of 14 in boost so I'm not going to beat on it too hard til I do some logging and get the tune tweaked, hopefully tomorrow.

Ya it sucks I blew the 4.8, but the 5.3 feels alot better down low/out of boost so I guess it's not such a bad thing. I will get pics and vids up when the final tune is done. Thanks for all the advice.

 

awesome keep us posted!

 

 

Glad to see you've got it running again.

 

Glad it's up and running again.

Laying rubber at 70MPH?? damn

 

if you seeing a/f of 14 in boost you better get a tune asap. you will end up w/ another blown motor.

 

Ya I know, it's hard to tell, my AF gauge seems pretty bouncy, but it's definately in the 13-14 range in boost. Would having open exhaust affect the AF ratio? I'm getting the exhaust finished today but up til now it's just been the downpipe wide open about a foot under the cab. When the exhaust is done I will start data logging and get blackbear to fine tune it.

 

Holy crap dude!! Your gonna blow another motor if you keep driving it iike that. The only reason your 4.8 blew up is because you weren't tuned for 20psi (ie it went lean and detonated). If you drive that 5.3 on a 4.8 tune your gonna do the exact same thing. The PCM is only giving you enough fuel to fuel a 4.8 @ xlbs of boost not a 5.3 at xlbs of boost, so of course your gonna run lean because there's a massive increase of air that the computer isn't preparred for and it can only correct 25% of it's fuel trims.
Your about to make another critical rookie error and blow a motor that is untuned, dont be so impatient or your gonna find yourself doing another swap soon.

 

Dunno how I missed the 13-14 AFR's in boost, but that's not good at all...

Shoot for mid 11's when you're in boost. And like Spoolin said, stay out of boost until it's tuned or you'll pop this 5.3 too.