What is an LQ4 or LQ9?
What is an LQ4 or LQ9? I am looking for a forged LS2 402. I want the aluminum block. Not looking for a 408 iron block.
I have seen some blocks for sale listed as LQ4 or LQ9? What are those? Iron or Aluminum? What did they come in?
I have seen some blocks for sale listed as LQ4 or LQ9? What are those? Iron or Aluminum? What did they come in?
LQ4 came with both iron and alum. heads. The 99-00 engines had iron heads everything after that was alum. The LQ9 had different pistons to achieve their higher compression and also better rods.
yes the parts are exchangeable. The LS2 and LQ iron blocks themselves are not the same. There are some revisions in the LS2 block that are more suitable for a stroker, I've been told.
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I am not sure how the "better rod" thing ever got started but they are the same rods. I can't remember the year but GM went from a fixed pin to floating pin design to try to stop the piston slap issue.
so if i have a m6 i might want to look for a lq9? i have a guy thats going to sell me a block that has some scoring but can be honed out (in one cylinder) and a set of heads he'll sell me for $400.00 there out of a 2000 truck. thats cheap as hell but hes hard up for $$. i want to put a procharger on maybe or stroke it. am i looking at the right engine
i am wondering about the flange that the guy in post #8 is talking about. what was the lesson?? 
He means the end of the crankshaft is longer which means your fbody tranny will have problems bolting up to, unless you modify the bellhousing, which would set the tranny further back which would screw up the fitting of everythhing else. Basically you don't wanna use that crank in your fbody.
He means the end of the crankshaft is longer which means your fbody tranny will have problems bolting up to, unless you modify the bellhousing, which would set the tranny further back which would screw up the fitting of everythhing else. Basically you don't wanna use that crank in your fbody.
Staging Lane
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The LQ4 and LQ9 blocks are identical. If you have to drill a hole for an alternator bracket in one, you will have to do it in the other as well. The 99-00 LQ4's have iron heads and a crank with a longer snout that is not compatible with any transmission other than a 4l80e that came behind LS style engines. The LQ9's were first built in the 2002 MY and had stronger rods and full floating wrist pins.....these were the predecessor and are identical to the LS2 stuff. In 2005, the LQ4 received all of the same internals as the LQ9. Both the LQ4 and LQ9 use the exact same 317 casting cylinder heads introduced in 2001.
Don't buy an early LQ4--you don't want the iron heads or the long crank flange. They are the same thing after that. LQ4 has a dished piston and LQ9 has a flat top. The floating wrist pin wasn't introduced until 2005 and it came along with the polymer skirted pistons to reduce the cold piston slap that is such an annoyance. The rods are no stronger--they are still powdered metal, just full floater. Almost any LS part that will work on an LS1 will work on them. They are NOT akin to the LS2 except that they displace the same thing, and that is about where it ends. You are talking two completely different generations of powerplants. Either one makes a suitable place to start from though.