LsJay04

I have a 06 Gto that decided to sling two rods through the block(ls2 and m12 transmission (variant of t56 I believe) trans is fine and so is everything else :/ , was looking to get a iron block 6.0 instead of another ls2 due to the arm and leg of a price on them , will any early 2000 iron block bolt up to my transmission ? Is there a specific block I should be looking for to have less of a hassle ? I know the lq4 is sought after but someone told me something about input shaft size being larger or something along those lines ? Just don’t wanna buy a block that won’t bolt back up to my trans/ harness and also make it as easy as possible when doing it .

CattleAc

iTrader: (7)

If possible maybe stay away from the 1999-2000 6.0's. They had the iron heads and longer crankshafts. They'll work, but the later ones will be easier. Anything after that is going to work fine. I've done a couple of 5.3-6.0 to M12/T56's. They'll work just fine.

LsJay04

Even the 5.3 ?? That was a thought for me from the beginning but also heard that they have different elector wheels or something which I know can be swapped . Sounds like I just need to stop listening to my “know it all” buddies . Also I plan on re using my 243 heads on the new engine , would those flow with the 5.3 well ?

CattleAc

iTrader: (7)

I've been under the impression that all the "GTO's" were 24X reluctor wheels. I could be wrong on this one though. Check to see what color your crank position sensor is. `If it's black, it's a 24X wheel. If it's grey. it's 58X. That's the definitive anwser.


Keeping the 243's are a good idea whatever engine you choose.

LS1Formulation

iTrader: (13)

The likelihood is that it's the hybrid Gen III/ Gen IV LS2, which had a front mounted 1X cam sensor and 24X reluctor wheel. OP, if you can find one, look for a 2005-2006 Trailblazer body style SUV with the engine code LH6. I bought a whole Saab 9-7X for $500 that had one, and as far as I can tell, the block is basically a 5.3 liter version of an LS2 ( it's aluminum ). It's also one of the strongest factory blocks made, with siamesed bores and super thick cylinder walls. You can bore them out all the way to 3.905" with no problem. I'm putting a T56 behind mine as well.