2000whitevert

iTrader: (1)

Alright guys i just came across a good deal on a ls2 long block im thinkin about picking up this weekend but first i want to make sure its worth it. Here are a couple of my questions/concerns....when sleeving a block for a bigger bore what is the advantge of a ls2 over a ls1 if any ? Also what are the main advantages of the ls2 block over a ls1 block if any? Id also like to know if i will need to change anything fuel/electronic wise??? Thanks for your time, Mike.

Tainted

iTrader: (9)

Ls2 uses gen 4 architecture, and has relocated sensors, as well as a different relucter wheel (58 vs 24 tooth)

Boring and sleeving wont make a difference, but the ls2 is defintely the way to go with the larger bore, updated sensor etc

2000whitevert

iTrader: (1)

Yea i figure for the price i am gettin this long block for (minus intake) it will be well worth it seeing how i wanted to do a heads/cam swap on my ls1 anyways. Now im sure its on here somewhere but i dont feel like diggin it up do you know off the top of your head how much better the 243s flow than the 853s??? This will be my first ls build and i see the 243s are greatly sought after i would like to do full cnc porting but im skeptical if they will hold a 250+ shot any thoughts on this???

Tainted

iTrader: (9)

Much better, especially with porting. You can mill for compression also

odarabla

iTrader: (1)

I have a LS2 403ci with the 24 tooth reluctor wheel. 2011 block but I built it that way..

2000whitevert

iTrader: (1)

Now this may be a dumb question but bare with me...what is the benefit of runnin the 24 tooth over the 58 or vice versa is it weight or?

blkbird2kta

iTrader: (3)

The reluctor wheel has nothing to do with weight. Gm just swapped to them in the gen4 engines.

Also it depends what the ls2 came out of and year. Some still have the 24 tooth wheel. The 05/06 gto's have 24 tooth reluctors.

As said above the only real differnece will be sensor placement. The map sensor will be relocated and knock sensors. You can always buy any of them and pull the crank and swap the wheel.

2000whitevert

iTrader: (1)

Ok. Well the one Im looking at is out of a '07 Trailblazer SS. Is the Ls2 block any stronger than the Ls1? Also I remember reading that the strongest blocks do not have windowed mains? I was considering an Lq iron block build but if this is just as good or close I like the idea of keeping an aluminum block in fhere.

2000whitevert

iTrader: (1)

So whats the bore x stroke formula for a 403ci? And whats the bore x stroke of a Ls2?

Tainted

iTrader: (9)

Those holes in the block are for bay to bay breathing. Its a good thing, and with what you want to do the stock block should be fine. You can always upgrade with arp bolts and new mains if you feel the need.

Johnnystock

iTrader: (6)

The biggest advantage of it is having more option for the bigger bore, like going with a bigger stroker, LS3 heads and intake for exemple. The rest isnt really a big advantage over the other..

5w20

iTrader: (21)

You seem lost. Are you planning on just boring the ls2 block or actually resleeving it?

2000whitevert

iTrader: (1)

Not lost just want to know my options. I'd like to resleeve for the bigger bore to do a 427 build. I can get this long block for $1000 with a spun rod. I will admit this is my first Ls build so I'm just picking your brains as knowledge is power and you guys are powerful. Want to try and do it as close to right the first time. Is there a better option? Ls6 or Ls7 block within the price range? I also like the idea of having the 243 heads to port and swap out my 853's with on my current Ls1. The 427 is going to be swapped in this winter. All advise is appreciated.

odarabla

iTrader: (1)

I bought a brand new block from GM and orderd my rotating assembly with a 24 tooth reluctor wheel.

odarabla

iTrader: (1)

The reluctor wheel has nothing to do with weight. It has to do with the computer. If you have a f-body and want to change to a 58 tooth reluctor there will be something you will have to change around to use it.

odarabla

iTrader: (1)

You can get a brand new undamaged LS2 block for around $1200.00 so don't waste your money one with a spun bearing. A LS7 block (which is what you should buy instead of sleeving an LS2) is going to cost you around $2500.00 and would probably be your best option for what you are looking to do. Anyone of the shops on this site can build you a 427 LS7 short block for around $6500.00 but you can get the stroker LS7 441ci for a little cheaper. Check out this site, this might help. Another option is to just buy a LS7 long block from Texas speed..

http://www.texas-speed.com/c-107-427...ng-blocks.aspx

5w20

iTrader: (21)

Sleeved 427 > LS7 427

1000 for a LS1 with a spun bearing is a bit steep.

How are you planning to make your power?

COPO9560

If you plan to build a 427 - why not get your current LS1 block wet sleeved and call it a day. This will be far stronger than an LS7 block. Look at ERL Superdeck or RED Darton sleeve process. Both suppliers can take your block and send you back a nice 427 or larger short block.

You could get the LS2 long block and dry sleeve it but most likely you would not use the rotating assembly, cam and heads anyway - meaning you paid $1K for a block with a spun bearing.

A 4.125 bore 427 is not a low cost build, make sure you understand all the costs before taking the plunge. LS7 style heads, new intake etc all add up quickly. An iron block 408 is a lot less money - big question is do you need 600 NA rwhp or not.

2000whitevert

iTrader: (1)

Yea ive been kickin it around i think for now ill just do the h/c swap on the ls1 then if i still want to get serious later in the year ill just use the ls1 block. I thought there would be more of an advantage to running the ls2 but from the sounds of it ill just be spending a g on something that wont actually benefit me right now.

COPO9560

You might want to put together a long term plan before going H/C. If you put these items on your LS1, they will be sub-optimal a 427 later - you will be lucky to get 1/2 of your money back. If the 427 is going to be real, consider supporting mods that you can keep - rear end, suspension, large tube headers ......

You could pick up the cheap LS2, add a 408 rotating assembly, have the heads ported by AI, add a large cam and be in the 500 rwhp range for a lot less money.