I am rebuilding my lq4 and came across a set of new ls3 pistons and rods for dirt cheap... My question is can it be done....Can I bore out my lq4 block to a ls3. I have done a lot of google search but no answer several people have asked this question on ls1tech and other sites but their threads had no good info.

 

There are a lot more guys on this forum that know how much an lq4 can safely be bored, than there are guys that know that plus know what the bore of an ls3 is. I think that .060" is the general consensus for max over size, I am not positive.

 

That would require boring to 4.065, I would pass.

 

I bored a 2012 ironblock to 6.2 and machine shop said I had meat left and it was safe. Motor sitting on stand now bout to go into a 67 chevelle. The lq4 block should have just as much meat but one thing machinist did say is that some blocks have the meat and others don't its on a block by block basis.

 

For n/a I'd do it. But any kind of power adder I'd pass.

 

Have block sonic checked some have enough some don't due to core shift etc... I've gone .040 on my stroker nitrous motor. And it sees a 300 shot everytime it's out.. Still livin, block is partially filled tho to bottom of waterpump holes. I think stock ls3 is 4.065 and most pistons are 4.070. I personally wouldn't do it if your using a power adder, but you could probly do it if it sonic checks with enough. Take block to a known LS machinist in your area and have block baked and checked and go from there. Be sure to ask if he has a deck plate!

 

N/A you will most likely be fine unless you have a block with serious core shift. My 6.0 block is half filled to the water pump ports and bored to 4.07". Stock 6.2 bore is 4.065"

Like stated above I would NOT go that far with a power adder. Stick with 4.03". You will never even notice the difference .04" makes power wise. But you will notice it if it goes BOOM!

 

A brand new aluminum 6.2l L 12623967 block can be had for $1470

peace
Hog

 

Ive dont a bunch of 6.0 blocks to 6.2, never had a problem with any of them.