A buddy gave up on a project he was doing and sold me these heads cheap. They need to be cleaned but sealing surfaces look flat without any scratches just some marks from the old gaskets, doesn't look like it needs machining. Says he started porting them and polished the chambers but I think he just buffed it with a wire wheel not a sanding disk so the chambers are still original. Without taking things apart I can see he did a light pass on the first 2" of the ports and didn't touch the bowl area. IDK what these are worth so price is negotiable, say $100 and shipping to start? Oh and the casting # is 12561706. LMK if you need more pics.

Edit- these are 5.3 heads NOT LS3. Also lowered the price since these appear to be worthless. =P
May be good for raising compression on LS1's because of the smaller chambers.

 

More pics.

 

One more.

 

You have a pm.

 

I don't see it for some reason?

 

those aren't LS3 heads they have cathedral ports and LS3 are square port possible LS2 heads but definitely not

these are LS3 heads

 

 

Ah, so these are 5.3 heads then. Thanks.

 

not trying to kill your sale but if someone bought them and then got all LS3 parts they would be out of luck because the rockers intake and throttle body are all different for the LS3 vs LS1-6

whats the casting number on the bottom left side of the valve cover

 

Ya, I need a mod to change the name to massaged 5.3 heads for sale. The casting # says they're truck heads so I dropped the price to $100. From what I hear these have smaller chambers than LS1 heads but need larger valves & porting to compete with better stuff. If I can't sell these I'll just take them back to my buddy and tell him I want his old garett instead.

 

would help to post what the casting number is on the heads as mentioned above.
5.3's can be made to be cheap potent heads with porting and good valve job if your willing to put some money into them.

 

if they are 317 heads then you have a good set of heads too

 

It's in the first post, 12561706.

 

There is a three digit number cast into the outside surface of the head, near the valvecover surface at a corner. That's the number people identify these heads by. Probably 706 heads from the number you posted, which are supposed to be very similar to the ls2 243 heads........

 

Ah above the exhaust port, shows how much I know about LS stuff. It's a 706, so not too bad then eh?

 

Any interest?

 

706 heads are great as long as they arent cracked. My machine shop informed me that some of them were made at a location that was known for cracking. I have had a pair that were cracked. Machine shops are able to repair them as well. 706 and 862 are 4.8 and 5.3 heads and flow the same as LS1 (853 or 241) heads even with their smaller 1.89" intake valve.

I love 4.8/5.3 heads. Its an easy and cheap way to bump compression.

$100 is what they are worth as long as theyre not cracked.

 

I was really let down when I opened this thread and it was 5.3 heads instead of LS3 heads for $100.

haha

 

haha! me too!

 

Are these still for sale? If they are not the Castech heads, I would be interested.

 

They're not castech, pm sent.