BAD2000TA

iTrader: (6)

I recently bought and received a set of heads off of Ebay that were advertised as 6.0Liter heads from a 2005 Trailblazer. I was thinking that those should be #243 castings. What I got are #799 Castings. These appear to be for the 5.3 Liter engine. How bad are these heads? Do they compare at all to the 243 castings? The exhausts are D shaped and I found that the chambers are 65cc. Can I use these heads on my 2001 Trans Am for any gain? I was planning on matching to the Z06 cam. Help please!!!!

Brian

camaroextra

iTrader: (10)

um the 6.0 liter heads are #317 castings. I duno waht #799 is, if they are 5.3 heads they need to be ported with some new valves or you wont see any gain. They are smaller.

bluecajun5.3

iTrader: (31)

5.3L's have 862 and 706 castings.

orangeapeel

iTrader: (18)

Gunnar was saying that they come on some of the 05-06 models. Some Trucks and stuff like the SSR. Sounds fishy to me. Get us some pictures if you can.

jfman

iTrader: (6)

the trucks(6.0) got better heads than us ?

Wnts2Go10O

iTrader: (12)

yup, ls6 heads with a 71cc chamber.

jfman

iTrader: (6)

What year 6.0 have the "good" heads ?

orangeapeel

iTrader: (18)

Sounds like its a *new* thing.

Gunnar@Patriot

iTrader: (20)

799 castings are used on 05+ 5.3 H.O. motors. These heads have 66cc combustion chambers and have a "D" shaped exhaust port like a LS6/LS2/LQ9 head. To the best of our knowledge, they weren't used on the 6.0 at all.

BAD2000TA

iTrader: (6)

What size valves are used? Can I assume that these will flow and perform very similar to the 243 castings? What about the valve springs? Standard LS1 stuff? Also, the casting is not SPM, as it's missing the little "triangles" by the spark plugs holes. Serious problem being sand cast?
Thanks!

SS_bnoon_SS

iTrader: (3)

Any year LQ9 6.0 has them... from Silverado SS and Escalade. I'm not 100% sure about the LQ4 heads though from the 6.0 HD trucks...

NemeSS

iTrader: (127)

4.8/5.3 came with 1.89 int. and 1.55 ex. valves

Lurius

iTrader: (7)

Saw this post when I was doing a search, might have some useful info, dont know. I work at GM and got to take a look at the rolling chassis of the new hybrid tahoe the other day. I have been told it has the L92 motor(for the gasoline power), and upon further inspection I saw it had 799 casting heads. Made me curious and I found this thread when searching for more info heh.

-Lurius

BAD2000TA

iTrader: (6)

Well, the 799 castings that I had were nothing like the L92 heads. They still had the cathedral-style intake ports; not the L-92/LS7 rectangular ports. I sent them back to the guy I bought them from and he refunded my money. I bought a correct set of #243 castings. L-92 heads also wouldn't have work on the LS1 block. Thanks for the update, though.

Brian