I keep reading more and more on these motors... I was under the assumption they are both 6.0L iron block Gen III motors. Is this true or what? What's the differences?? Will '98 perimeter bolt heads work with them? If so, I'm assuming you just use the '98 graphite head gaskets?? Thanks for the help, I feel dumb posting this but I can only find so much info with the "search" option on here.


thanks!
-Jeremy

 

youre better off with the 6.0 head gaskets. also the LQ9 and LQ4. the difference really is the pistons. the LQ9 has flat top pistons and has a compression of 10.1 and the LQ4 has a compression ratio of 9.5. same cam, heads, springs and etc. i did heard that hte LQ9 had better rods but mainly its the pistons that get you the power difference.
and your better off with the 317 heads since they flow the same as teh LS6 heads only difference is that they have 72cc and hte 243 heads have 65cc i believe

 

Like Pewter said, the LQ9 has Flat top pistons, they do have beefier rods and floating wrist pins. Other than that, they are basically identical. Also the 317 heads on both are the same.

 

So how do you know which motor is which by looking at it??

Also, as for the '98 heads... I know you have to run '98 gaskets with them on newer LS1 blocks because of some "notch"... with the newer head gaskets they will leak or something. That's why I was wondering if the same thing applies to using them on a 6.0L. Maybe I'll just get a 6.0 and port the 317's and sell my old '98 heads.

Thanks for the info so far!!

 

What notch. YOu need to run a 6.0 gasket on a 6.0 motor. You do not want the gasket hanging into the chamber bad things can happend there.

 

****... I forgot about the difference in bore size between a 5.7/6.0L... all I know is that if you run '98 heads on any 5.7L that you HAVE to run '98 gaskets... other ones or newer ones will not work because of some "notch" that will cause a leak. I have 2 or 3 buddies that made the mistake of running the wrong head gaskets on their '98s.

 

Can you take a pic of the NOTCH I do not have an 98. I have 02 block 6.0 lq4 block with 243 ls6 heads. I have never herd of this notch and i have been working on these motors for a long time but i have never work on a 98 funny hu.

 

I had a faxed picture of the "notch" from Futral Motorsports. I don't know what I did with it, but being it was a fax you couldn't hardly see it anyway.

 

No, I'm not actually familiar with it... I've just taken the advice from a few very knowledgeable people.

 

You can't tell any difference by outside visual inspection. You'd either have to know for sure what vehicle it came out of, or pull the heads.

 

I see, thanks!

 

notch

 

What the hell... how does that cause the head to "leak" if you use the newer gaskets??

 

Yeah, that's what I was wondering. I've heard it creates a collant leak.

 

Same here... I'm wondering if that little notch is covered by the new head gaskets but has another coolant passage cut out on it. That would let the water flow right on out. LOL