i know that nothing will hurt the truck however i was wondering how much my truck will run like **** and how bad my mileage will be after the install of the LT's with ORY and no tune... i plan on retuning the truck soon... however i will have a window of time to put the LTs in this saturday and want to get it done...

another thing... i was wondering if there is anything i should watch for when installing these bad boys... or any tricks to any problems i may encounter... are my manifold bolts going to break while i take the stock manifolds off? can i spray them down with PB blaster to loosen them up or is that a waste of time? are the supplied gaskets good or are they junk? should i use the high temp copper sealant they are suggesting on the gaskets? just any general help to make this install quick and painless would be greatly appreciated... BTW these are going on a 05 avalanche z71...

 

Rear driver side manifold bolts tend to break. Mine did. I live in the country so stock y didn't want to come out easily because of years of dirt and rust around bolts . So if you don't plan on putting them back on just cut that crap out. Speeds things up a ton. Truck should get around but not at its best. Needs re tuned

 

yup my driver rear bolt broke off on its own.. didn't figure it out til i had a leak on the stock manifolds.

i have LPP's also the second cylinder on the driver side the plug boot will hit. get some sleeves to put over the plug wires to keep from arcing..

the driver side i put the header from the top of the engine down and i put the passenger side from the bottom up. seemed to be a lot easier. i ran for about 4 months with out a tune

 

Sounds like a nightmare if the bolt breaks off in the head... I've done tons if work to various cars however never had to deal with a broken bolt in the head... Any tricks to get it out if that happens?

 

I left mine lol doesn't seem to leak

 

none of mine broke, maybe i was lucky? or maybe if they break off just buy aftermarket heads.....

 

I got 70kmc on the truck and it's been through winters.... However the bolts look like just slight surface rust on them....

 

I left mine as well. hasn't leaked for over. a year now. mine had roughly 110,000 when I did mine and salty nasty winters in IN only lost one bolt on the swap didnt use any penetrating lube

 

Start soaking the bolts now with some PB blaster. Also spray them down and go for a drive to get the manifolds nice and hot so the PB soaks into the metal. Soak em before you go to bed once the truck is cool. Do the same for all the bolts for the exhaust. It never hurts. If one breaks off you could get lucky and you can grab it with a pick and spin it out. Two of mine broke off on their own. I managed to get one out. I said screw the other one. Other then that I was able to install mine from the bottom up with no problem. Also reuse your factory manifold gaskets as long as they are still good. Dont use the LPP ones.

 

I had driver side rear break on my 4.8L and when we were doing the 6.0 swap the driver side rear broke as well... We just tapped out one that broke in the head and used an insert to help with the threading of the new bolt. Also using Stage 8 locking header bolts. I had been running with a broken header bolt for about 6 months and the ticking was getting worse and worse every day. Very annoying and it made my truck sound "cheap"..