After searching for a good used LS2 block I am leaning towards buying a new GMPP unit. By the time I take a used block to the machine shop and have all of the necessary services performed, I am at the cost of a new block shipped to my front door. However, that leaves me with some questions that I have not found in my searches that might make or break my decision. Does anyone know the answer to the following?

1. Do new GMPP blocks come with cam bearings installed?
2. Minus a final cleaning/thread chasing, is the block ready to build out of the box? Meaning, can I trust that the block is dimensionally stable without taking it to a shop for final machining (trust but verify).

So far, it seems almost a wash to service a used block rather than just going new. This is in preparation for a N/A 402 build.

Thoughts?

 

Welcome to LS1tech!

This block (12602691) comes with cam bearings installed and a finish bore size of 4.0 inches.

Myself and certainly others would highly recommend that you make friends with a local machine shop and discuss pistons and rings. They'll need to bore and finish hone the cylinders to match whatever piston & ring package you get.

If you're new to this, let the shop assemble the short block for you. Everything else is a bolt-on affair with little measuring and checking.

 

Very good advice...especially the part in RED if your the least bit unsure of your ability...

 

Where are you located?

I have an LS2 block that I am going to sell, I just haven't listed it yet. I'd rather not ship it, but I can for the right price. The one I have has been fully machined, and the bores are at 4.010". It would, as would any block (as the above posters are commenting), need to be final honed based on your pistons. I also am including a set of ARP main studs with it.

You can PM me for more information if you are interested. I'm located in Texas.

Otherwise, I think you will find that most, if not all, builders will want to do a full set of machining steps to a new block. You will for certain want to do a hone on the cylinders. I would want the mains to be checked and likely honed as well. While you would expect everything to be ok from GM, I'm of the mind that I'd much rather check and verify than to rely on someone else's work. Maybe it's the engineer in me.

 

What's a LS2 block go for?

 

http://www.texas-speed.com/p-578-gm-...ls2-block.aspx

 

Thanks for all the replies, and I think I have my answer. I was 95% sure I needed to have a final hone on a new block, and you guys have confirmed that. GM advertises that on the LSX block, but not the others. I too like to verify (the engineer in me too), but knowing the longevity of these motors I didn’t want to pay for a triple check if there was enough evidence supporting elsewise.
This is not my first motor build (plenty of SBC stuff), albeit it is for an LSX platform. I am fairly confident in my abilities and have been researching and reading LSX build books for years now. Nothing in the process seems out of my comfort zone, except proper block prep.
I have spoken to a few shops around here (southwest Ohio) with LSX build experience and I am confident they can do the work appropriately. As to the post about used LS2 blocks, I have seen them go for $500 to $800. With $500+ in proper machine shop activities you can quickly price yourself out of a new block ($1200). I have found this to be true with any aluminum block, 5.3, 5.7, 6.0, 6.2 with the only cost difference in the initial price of the used core. The displacement doesn’t seem to alter the used value of an aluminum block. This is why I would like to start with an LS2 block. The price difference is moot, compared to other aluminum blocks, and I might as well get more bang for my buck and have greater cylinder head options. That is unless I score a good deal on an 5.7, or 5.3 al block, which after scouring the adds for years I haven’t been lucky.

 

http://www.ebay.com/itm/LS2-6-0-alum...-/270985176790