on a 99 LQ4 (came with iron heads) isnt there something different about the length of the crank or something...?? i have access to one but thought i had heard something like this. woyuld like to bolt it up to 2wd 4l80e..... also would a '06 LS2 crank and rods go into the 99 LQ4 shortblock? (as this would be a benefit correct, as the LS2 came with better rods... is the crank any better?)

From what I understand the 99 uses a shorter crank and runs the GM spacer to achieve the right mounting location for a tq converter.

Doesn't the LS2 use the 58x crank wheel vs LQ4s 24x or something?

Actually the '99 and '00 LQ4's use a slightly longer crank which will mount up to a similar year 4L80E, or a 700R4, TH350, or other sbc style trans. Its the newer blocks that had regular length cranks and a spacer to mount up to the 4L80E. If you were going to use a T56 you would need to swap the crank for a newer LQ4 crank, or an LS1, LS2, etc. The LS2 cranks did have a 58x reluctor wheel but it is easily changed to a 24x. This is what I did with my '00 block, took the reluctor wheel off the stock crank and put it on an LS2 crankshaft. But it looks like you want to use a 4L80E so you won't need to go through all that trouble anyways. The only thing I am not sure of is if the input shaft and bellhousing is the same for a 2WD and 4WD 4L80E.

As for the pistons and rods, when I took mine out of my block the rods were the same type as an LS1, the "cracked" rod kind. So if those are what comes in an LS2 then you get no benefit of changing them out. Now, the pistons should be different...I believe the LS2 pistons will bump the compression up from the older ('99 and '00) LQ4 pistons.

My advice is if you're going to pull the pistons out, you should go ahead and replace all the bearings in the block while you have it taken apart. Or on the flip side, get a newer LQ4 or LQ9 with the higher compression pistons and alum. heads, plus you can still use a 4L60E since it will have the crank spacer.

You will find that parts in Gen III blocks are interchangable in a very drastic way, basically everything except for the pistons only because the 5.3L pistons won't fit in a 6.0L, etc. If the bore size is the same, pretty much everything is interchangable.

thank you very much. that does help me out some.

so as far as the crank goes... if im using a 4l80e theres no need to change the crank, right? (theres not a significant difference in strength between the 99-00 and 01++ cranks?)

as far as the rods go, i could be wrong but i thought that GTO LS2s and LQ9s used a beefier rod... could be mistaken.

and as far as pistons go im turboing this motor so i definately dont want higher cr.

aqnd i will be putting al. 317's on it if i decide to use this longblock.

thanks again guys!

A crank is a crank, when you're talking about original parts anyways. A '99 truck crank is no stronger or weaker than a stock LS1 or LS2 crank. They're made of the same metals.

But the '01-up cranks were machined to tighter tolerances, and none of the '99 cranks had any hollowed journals. So the '01-up cranks really are preferable, up to about 800 horses. From there, go 4340 forged.

so the if i can get an 01+ LQ4 crank off ebay for a $100 is it worth it...?
or just stick with what i got for now....

where are people finding these pullout engine deals for cheap, where i live even the 5.3's are over a 1000.00 for the most part......

all id like to get is a low mile 5.3 or 6.0 liter long block, and run it for now, while i (long term) build the 99 6.0 i have access to thru a friend as a 370 forged shortblock...............



thank you for the help

try www.lkqcorp.com. They're in every state, and my local one sells complete LM7s (5.3L) for $500. By the time I paid sales tax, core charge, gas for the 300-mile round trip, and lunch at a burger place, I was still out less than $625. That was my first LSx. My second was a lucky find at Pick-N-Pull on half price day, it had fire damage to the intake, and was an '00 LM7, but for $80 out the gate, I took it.

thank you very much ill check it out.