mickeyg

Hey guys,

I recently bought a gen 4 6.0 off the old facebook market place. When I was picking it up I didn't even think to see if gen 4 6.0s came with 317 heads. I did some googling and it seems like all the gen4 6.0s came with rec port heads.

Did any gen4 6.0s come with 317 heads or did I get got?

Thanks,

G Atsma

The Gen IV's that have cathedral port heads have 243/799 heads, so it's a win-win.
Same ports, smaller chamber, compression adjusted by dishing the pistons.
You were not had...

mickeyg

It's an iron block not an LS2, so it should be an l96, ly6, or lc8 right?

G Atsma

Any Gen IV 6.0 w/ cathedral heads will also have an aluminum block. There were three- the LS2, LFA and LZ1.
You're right- the ones you mention have iron blocks and rectangular heads.
What is the intended usage for your engine?

mickeyg

It's replacing a gen 3 5.3 that lost oil pressure. I'm only shooting for about 500hp so I'll probably freshen up the block, use the 241 heads that are on my 5.3 and the ss2 cam. Bummer I didn't get the bigger heads, but on the bright side I don't need to buy an intake

G Atsma

You never said which engine you ended up with.
If you use the Gen IV 6.0, you will need to relocate the knock sensors to the side of the block, and the cam sensor is now on the timing cover. You will need to switch the 2 outer wires on the sensor plug for it to work with your wiring harness.
No matter which engine you got, both the 243/799 cathedrals and the 823 rectangulars are way better than the 241 heads you mention. Stick with the heads that come on the engine.

mickeyg

So the car is an 85 trans am that currently has a gen 3 5.3/t56 with a terminator x max.

I *think* it is supposed to be an LY6. it came out of a 2011 express van. Has the VVT timing cover and stamped '6.0 IV' on the passenger rear. I'm really just bummed I didn't get the rec port heads since they flow so much more.

$500 isn't bad for a gen 4 short block. But I guess we'll have to see what the machine shop says before I get too excited

G Atsma

The LY6 HAS rec port heads! But they weren't made after the 2010 model year.
Was the van set up for CNG/LPG? It could be an LC8 also iron block/rec port heads.
Or the L96 was made that year, also iron/rec port heads.
If it has an iron block it does NOT have cathedral heads. LS2, LFA, and LZ1. We have gone over this.
If you got a Gen IV iron block with original heads, you HAVE rec port heads!

Ls7colorado

iTrader: (3)

It sounds like he bought a 6.0 off marketplace that has 317 heads already on it....

BUT the seller said it was a Gen4 6.0 and he said it is stamped "6.0 IV" and has a VVT timing cover.

So it is probably a gen 4 6.0 that someone robbed the 823 heads and slapped a set of 317 heads on to sell, so I would be fairly concerned about what is under those heads.....

G Atsma

Good call! Might be a junkyard switcharoo...

mickeyg

Okay I took some pictures because I don't think that I'm explaining it right.

Ls7colorado

iTrader: (3)

That definitely looks like a L96 bottom end, but I still have never seen one with 317 heads.

01CamaroSSTx

iTrader: (3)

317's came on Gen III 6.0's and Gen IV 6.0's had the 823's so you have a Gen IV block and Gen III cylinder heads

68Formula

L96/LY6 short block and LQ4/LQ9 heads.