are the the ls3 blocks better then ls2. looking to start building my new motor.

 

They have a larger bore. They should be less durable in a FI application, at high HP levels as a result of this.

 

Actually, they're set up for FI, as the LS3 is the basis for the LS9 in the supercharged ZR1. LS3+GM supercharger=LS9.

 

i would say the ls2 F/I would be stronger, than the ls3 F/I but not a big enough difference....

im sure the ls3 will run you a lot more money so just get a ls2 and save your money!

 

The ZR1 block is a different block than the LS3..

 

the ls9 block is different,but anyway the ls3 block is in no way weaker than the ls2,sleeves are the same thinkness and they are about the same price new,go with the ls3,bigger bore is always better

 

how big can you bore a LS3 block? ,factory bore a 4.065" right ?

 

If my memory serves I beleive that I read in the GMPP catalog that they could be bored 30 thousanths. Not going to pick up much displacement with that ... I would save that in case you had to clean up the bores on a rebuild down the road.

 

I should have elaboated further it seems. it WILL be weaker at extreme power levels due to reduced material between the cylinders. Less material equals less strength everytime when all other factors remain constant. This will not have much affect a mid level power biuild (600hp or so)

 

from my local dealer. i can get a ls3 cheaper then a ls2 it is about 200 dollars cheaper

 

shawn, can you get me the gm part number or both the ls3 and ls9. cause i think they are the same block. just different internals

 

Kind of odd that you can get an l92/ls3 block cheaper since the L92 block lists for 1,821 versus 1,393 for the ls2. Online I saw the ls2 as low as 999 versus 1350 for the ls3.

 

Those are prices for just the blocks. Who here makes complete engines based on LS2/LS3 blocks?

 

Just about very site sponsor that builds GenIII based engines. Look tot he right

 

Really?!? How much can you get the LS3 block for? I might have you pick you up for me.

 

They are the same displacement with the same bore and stroke (376 cu. in.) but not the same block.

 

That SC from the LSA or LS9 should bolt up right?

 

pm me your phone number

 

Don't know if anyone saw this(from corvette blogger.com). I was thinking about using this block in a forced induction application. Seems like pretty good news and a good alternative to the LS7 block assuming you choose not to go with the LS7 heads.

Corvette's Chief Engineer Tadge Juechter Hosts A ZR1 Chat

CDINGERS:
What changes to the ZR1 LS3 block will carry over to the production LS3? Oil Squirters, 11mm head bolts, etc.


Tadge Juechter:
The block structural improvements and the improvement in bay to bay breathing will be included in LS3 blocks for 2009.

 

From what I've seen, the aluminum 6.2L blocks suffer from a sort of "core shift". Like the aluminum is cast around the sleeves, and then bored offset leaving one side of the sleeves thinner (as in .070" thick) and the other thicker. Our shop rejects blocks all the time for such problems.

The LS2 blocks seem spot on 99% of the time. I personally feel the LS2 is the better of the two.