1FastBrick

iTrader: (17)

You can go 1 of 2 ways.

1. If everything is withen spec re-ring, hone cylinders and new bearings.

2. If its on the lose side. Go .020 over with replacement pistons, new rings, and freshen up bottom end.

Either way replace the factory rod bolts!!!

On the heads, again It depends on what your looking for. You can mill the factory 799 heads to bump the compression some. Depending on what you want to spend. If you want to keep it mild a bowl blend will do the trick just nicely. Get some factory Z-06 Springs and a mild cam.

Its so tough to say this is the perfect cam for you for your application. I was looking for a little more performance with no trade off in low end. I was looking at the comp 265 low lift cam it slike 212/218 .525/529 on a 114 with 2 degrees advance ground in.

For gas milage you may want to stay at or just under that. There are a few cams that are specd more for towing and milage but its been a while since I looked at the comp specs... get a professional tune when it's all done so you can get the most out of your new package.

ig109

Sounds like a healthy recipe..

Any projections as to the power of this combination?

I will say that i will likely go with a set of ported 862 heads. Unless it would be cheaper to send my 799s in for a mill/rebuild?

1FastBrick

iTrader: (17)

Well that depends on the labor and parts to rebuild your current heads. I would say around $500 $600 depending on your machine shop. but you could also sale them and get some ported heads. Lets say you get $500 for them, you could put that towards the ported 862 heads.

1FastBrick

iTrader: (17)

Oh and I bet you would gain an easy 60-80 Hp at the wheels.

1FastBrick

iTrader: (17)

I would recomend talking with Pat G and possibly haveing him spec you a cam specifically for your needs and the package you want to put together. Its only $25 and it will be tailored to what you want. Pat G is on the LS1Tech side. He is very knowledgeable regardeing cams.

ig109

Thank you, I will do just that.

spent21

iTrader: (3)

Someone recommended earlier punching the bores out to a 5.7. This is possible on the iron block 4.8/5.3, but the L33 is the aluminum block, yes? I read once that the maximum recommended overbore on the aluminum blocks was +.010 unless you replaced the sleeves.
Was I misinformed?

1FastBrick

iTrader: (17)

Please start a new thread to get the info you are looking for.

Kemble

iTrader: (1)

Seems like a legitimate question that pertains to this thread. You said. 020 over, he is asking if the aluminum block can go that far.

spent21

iTrader: (3)

Let me say that I'm not building this engine. I merely stated that I remember reading somewhere that the aluminum block was not able to be safely bored greater than +.010" and would like the clarification, that is if someone here knows, that the same is true for the aluminum L33.

In fact, I looked up the info that I remember reading:

"The 1997 and 1998 LS1 5.7liter blocks had thinner cylinder sleeves, so one drawback of these engines is they cannot tolerate a lot of cylinder machining. The limit for these blocks is 0.005" overbore, while all other 5.7L blocks are allowed 0.010inch."

The material goes on to address 5.3/4.8 blocks:

"One thing to note about the 4.8L and 5.3L blocks is the cylinder wall thickness. They have enough material to be bored out 0.120" to stock LS1 displacement. So with the 4.8L or 5.3L block, one could have the same engine displacement as the aluminum 5.7L but with a cast-iron block."

How to Build and Modify GM LS-Series Engines - Joseph Potak (pp 8 , 10)

Now I realize that I'm connecting dots given this information. The + 0.010" referenced was for the 5.7L LS1 aluminum block; however, the 5.3L aluminum engines were not addressed directly.

So my question (as I see it) is legitimate and still stands if it saves the OP the headache of starting down a dead end road.