sbf2

hi guys I have a 07 Tahoe with a 5.3 that's gonna get rebuilt engine.not sure if its iron or aluminm but want to bore it to a 5.7.seen a few threads where people did it and around 50-100 miles they started having blow by.has anyone did this with a daily driver engines

G Atsma

If you can find the engine code, aluminum would be LC9, or LH9. Others are LH6 and LH8 but they went into other vehicles.

Shawn0331

The gap between cylinders isn't going to be any smaller than a regular 3.9'' bore ls1. Only thing you run into is cylinder wall thickness, which is why people re sleeve them. If you're not boosting or throwing nitrous at it i think you will be fine.

sbf2

anyone else

B52bombardier1

Don't buy anything for this block until your machinist tells you there has not been any core shift that occurred during original casting. Most of these iron blocks can be bored to 5.7 but not all of them. Let your machinist figure this out for you.

Rick

slowride

iTrader: (3)

Blow by is one thing, but if you had bored it too much you would have way worse issues to deal with than blowby. I'd say some of the people with issues either have operator error or poor machine work.

sbf2

its just gonna be my travel vehicle and hope to get 1-200k miles on the rebuilt engine

Ls7colorado

iTrader: (3)

I would seriously just consider getting a 100-150K mile sludge free 6.0 from a salvage yard

sbf2

Ls7colorado

iTrader: (3)

eseibel67

iTrader: (10)

Because its a lot cheaper and easier to replace with a better engine than to put a lot of parts and labor into an existing engine. These things last a long time, theres not much risk in a used 6.0 if it checks out.

sbf2

I was told I would have to get a 07 and up 6.0 with 58x and all the engines I found are $1800 plus with 150-200k miles I can get the 5.3 rebuilt for 1800 and that's freshened the heads,new pistons and re assembled out the door

C5SixSpeedZ51

If the 5.3 is aluminum I would just rebuild it if I were you. You Most likely have 799 or 243 heads which is a big plus. If You happen to have a 5.3L L33 it came with flat tops with around 9.9.1 compression You could mill those heads a little to get up around the 10.5.1 Compression area, if you're looking to PEP its step up a little. Lol The Iron Blocks are around almost 100 lbs heavier than the aluminum engines so keep that in mind as well.

sbf2

Basically I just want something reliable for my family and since I had to rebuild it I was just gonna change it a little so I think it's best to just rebuild it and just do the cam motion drop in cam and leave it alone

C5SixSpeedZ51

It will be plenty of Motor for You and Your Family
Good Luck and Let us know how your engine turns out bud.

sbf2

Thanks I sure will