Difference between the GM 6.0's?
I was planning a 6.0 swap in my f-body, and was wondering what the difference is between the 3 GM 6.0 Engines. Just in case, they are the LQ4, LQ9 and LS2.
out of curiosity, what year/model fbody do you have? and nice user name btw
LQ9: Gen III. iron block, flat tops, better rods, 10:1 CR, 317 heads
LS2: Gen IV, AL block, flat tops, better rods, 10..9:1 CR, 243 heads
The LQ4 and LQ9 are the same save for the pistons and rods.
The LS2 is Gen IV and will have front mount cam sensor side knock sensors and may or may not be a 24x crank trigger.
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Check at http://car-part.com/ for a engine. I found my 08 LY6 w/ 30K CHEAPER than most salvage yards wanted fo 40-75K LQ4s or 75-100K LQ9s
. If you do score one, snag the ECM too. Remember.... LY6s are the replacement LQ4 but w/ 9.6:1 comp. ratio and the L92/LS3 rectangular heads already installed. Its a no brainer in my book. Cheaper and better. 
Here is one guy who did. (his car was a v6 too I believe) https://ls1tech.com/forums/conversio...d-formula.html
Check at http://car-part.com/ for a engine. I found my 08 LY6 w/ 30K CHEAPER than most salvage yards wanted fo 40-75K LQ4s or 75-100K LQ9s
. If you do score one, snag the ECM too. Remember.... LY6s are the replacement LQ4 but w/ 9.6:1 comp. ratio and the L92/LS3 rectangular heads already installed. Its a no brainer in my book. Cheaper and better. 
Here is one guy who did. (his car was a v6 too I believe) https://ls1tech.com/forums/conversio...d-formula.html
Oh yeah, I WAS wrong
. His car was a LT1 car. Not a V6 mybad. LOL. Are you sure the LQ9 has beefier rods than the LQ4? I have 2 LSX motor build books and neither one of them says anything about LQ9 rods being any beefier at all. They both say all the LS motor rods are the same powdered metal, then forged rods & cracked for rod cap fit. The 1999 and beyond rods have better factory rod bolts and LS1/LS6 rods have full floating pins. I have heard this beefier rods rumor from someone else but it was just guys talking. Does anyone have any specific written proof etc the LQ9 rods are beefier? No offense. I just l want to know for sure.
Hpbob
Are you sure the LQ9 has beefier rods than the LQ4? I have 2 LSX motor build books and neither one of them says anything about LQ9 rods being any beefier at all. They both say all the LS motor rods are the same powdered metal, then forged rods & cracked for rod cap fit. The 1999 and beyond rods have better factory rod bolts and LS1/LS6 rods have full floating pins. I have heard this beefier rods rumor from someone else but it was just guys talking. Does anyone have any specific written proof etc the LQ9 rods are beefier? No offense. I just l want to know for sure.
Hpbob
Been awhile since this came up but there is lots of info here and on PTtrucks.net about it.
This whole family of engines was designed with three different bore sizes and two different strokes, so GM only needed two rods, a long one and a short one, to cover all four different displacements, but they ended up with three different rods anyway. These rods are all powdered metal forgings with cracked caps and they all had press-fit pins, except the ones used in the 6.0L LQ9 engines that came with full-floating pins. And, it appears that all the Gen III/Gen IV motors (a Gen III motor with "displacement on demand" is called a Gen IV motor) went to full-floating pins in '05 according to some car magazines.
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The Long Rods
* The 4.8L engine used a "long rod" that measured 6.275? center-to-center because it had a shorter stroke. Look for a 121BW casting number on the side of the cap.
The Short Rods
* The 5.3L, 5.7L and 6.0L all used the "short rod" that measured 6.096?, center-to-center, but there were two different short rods used for the 6.0L engines.
The 5.3L, 5.7L and the standard LQ4 6.0L used the 143 casting that was rounded off on one side of the shank and squared-off on the other side. Our sample rod weighed 609 grams.
*
The LQ9 version of the 6.0L that was used in the Escalade and Silverado SS came with the 123/145 casting that had a thicker beam, a stronger big end and a bushing in the small end for a full-floating pin. Our sample weighed 645 grams.
*
The original rod bolts in the 5.7L were more than adequate to start with and they were upgraded to take 450 hp in '99, so they're pretty reliable, but rebuilders should consider replacing all of them with ARP bolts when building a high performance motor.
*
Just for the record, the only parts from the Gen II engines that were carried over to the Gen III were the rod bearings; they're the same for both families. ]Rods
This whole family of engines was designed with three different bore sizes and two different strokes, so GM only needed two rods, a long one and a short one, to cover all four different displacements, but they ended up with three different rods anyway. These rods are all powdered metal forgings with cracked caps and they all had press-fit pins, except the ones used in the 6.0L LQ9 engines that came with full-floating pins. And, it appears that all the Gen III/Gen IV motors (a Gen III motor with "displacement on demand" is called a Gen IV motor) went to full-floating pins in '05 according to some car magazines.
Either way, the LY6 is the clear choice for the even remotely budget-minded. What's not to love? L92 heads, stronger rods, iron block for strength, oh and variable valve timing. Since I've been driving mine on a daily basis, I can tell you that this thing is truly awesome..... it doesn't matter what gear you are in, it always pulls and it pulls REALLY hard.
If I can get 400+rwhp on 89 octane gas then I'll be happy... 9.6:1 compression is such a nice thing
Oh, and the other nice thing about the LY6 is the compression... so if a turbo, procharger or TVS is in your future - this is your motor.edit: oh, and just a big FYI to everyone considering this swap... the ideal candidate is going to be a 1998 f-body or 97-98 vette (or even 1999 f-body I think) - whichever cars of those years that utilize analog gauges plus have the oil pan, accessories and all that stuff necessary for the swap... the same goes for swapping in a L92.
On the front on the drivers side of the block, I believe it says " IV 6.0L " It says the same on the rear of the pass side block. ( bare in mind that this is from memory. So what it says might be SLIGHTLY different.) LY6 or L92 are gen IV motors. The eariest I believe they are offered is late 07 ( new body style)









