What is the story for the "LS7 type" small bore head. I know that the L-92 head is for a smaller bore but will not fit a 3.90 bore. I just want to make sure i am not waiting for something that is not happening.

-Paul

 

As far as I know the L92 head is a big bore. The L92 has a 4.06 or something like that.

 

I Think it is being made to fit bores as small as 4" (the 6.0L) I would expect to see it used on the base corvette with a bump in power sometime in the near future. Sucks for us 5.7L folkes.

 

Those bastards!! oh well back to look at darts and afrs

 

im sure someone will weld them for use with 3.90's

 

I sure hope not!!!

 

is the 5.3 that is in the monte and the impalla the same one from the past few years?

 

so could you use these on an existing 6.0L with a 4.03 bore?

 

GM press releases have shown the L76 and L92 use the new head design.
The L76 being the 4.000 bore 6.0L and the L92 being the 4.060 bore 6.2L
http://media.gm.com/servlet/GatewayS...39&docid=21579

It should not be a problem to place the L76/L92 heads on a 4.000 bored LS1 (race prep'd and rework'd), a 4.000 to 4.030 LS2 block, or even on the Cast Iron Vortec 6000 block.

Just have to wait for a square bore intake manifold

The LS7 has a rectangular shape
The LS1/LS6/LS2 has a Elongated Oval...
The L76/L92 is a rounded edge Square (top and sides are equal in length to height).
http://gm.wieck.com/forms/gm/previewpage?026561 (in the photo you can see the manifold runner is a rounded square and photo's of the heads show it to be a rounded square intake port... just can't find a photo of the head's intake port at this time)

The 5.3 in the Impala SS and Grand Prix GTP may be using the 243 casting heads (LS6/LS2) with solid valves. It has been stated in the same GM press release that listed the spec's for the L76/L92 that the 4.8 and 5.3 motors would recieve revised heads like the LS6...

Looks like GM is simplifing the components in the catalog... drop the old LS1 head design which was used on the 99 to 04 4.8, 5.3, and 6.0 go with the 243 casting design for the 4.8 and 5.3 and the new head for the 6.0 and 6.2 motors (slated to start in 07 SUV line).

One of the threads on here is about the LS9 in the thread they talk about a LS8 that would make around the 450 to 475 range...
If I had to guess I'ld say the LS8 may be the new L92 truck motor with a hotter cam and a low profile manifold (been thinking it would be called a LS3 though).

 

I'm kinda intersted in the L92 head. Some folks ahve complained aboutt he Ls7 heads and the intake valve being too large, and causing issue with the exhust side. I'm wondering if a more reasonalbe intake valve size, along witha better exhaust side will make this head a solid performer.