dhdenney

iTrader: (53)

Yeah, just curious as to what this was. All I wanted to know is what made it different. So with that outta the way.... is there some obvious differences that you can see with the DOD and VVT? It's interesting to see that GM produced another 6.0 block when they already had the LS2 out.

Bo185

I bet it's the new Vortec max motor block in the 07 trucks and it's RPO coded L76 BTW. It may be on of those blocks since the part number itn't in the system yet.

Bring the Noise

A quick way to tell between a DOD and NON DOD motor would be the solinoid mount points in the valley.

On the LS2 they are there but were not drilled out (ie no oil flows threw them). On the Vortec Max (L76) or any other DOD Gen IV they will be functional (IE if you don't cap them off oil will flow through them and throw off your oil pressure reading). Damn shame you can't hook up a pump to see if it flows or not.

The thing I hate the most is the page is blocked at work so I can't see the images until I get home.

Bo185

It's got the DOD holes and they are drilled.

JMBLOWNWS6

iTrader: (17)

Even if it has DOD Just use the proper valley cover and it comes with O rings to seal them. If you want to go the extra mile tap them and plug them. Its kind weird how it is painted.

Bring the Noise

Plug em, seal em, or tap em and plug em, or duck tape em (okay don't do that last one).

Sounds like the L76 block, and that is about the only difference between the LS2 and L76 block.

It's a shame it wasn't a 4.065" bore L92 block (then you could put together a 414).

DoesSpeedTurnUon

iTrader: (17)

Yea, i was kinda hoping it might be, but then it'd say 6.2 on the front

mbrouder

iTrader: (2)

Can someone post a pic of where exactly these holes are that need to be plugged?

Steve - Race Eng

iTrader: (1)

The 6 L and 5.3 L truck blocks have solid main bearing bulkheads, no cast in breather holes. They are stronger than other production blocks for that reason.

I got one in to sleeve about a couple of years ago. I thought was some sort of factory prototype piece. A short time later I found out it was a production truck casting.

The lack of breather holes causes a horsepower loss at high rpm (roughly 20 hp according to one of my NHRA stock eliminator customers) unless you run a good dry sump system capable of pulling a vacuum in the pan in which case there is no loss in power - tested by one of my shop customers on his dyno.


I have sleeved a good number of these blocks for big inch applications. There is one casting number 12569513 5.3 L that has non siameesed Gen III cylinder walls making it unsuitable for dry sleeving. I have not run across a 6 L block casting with non siameesed Gen III cylinder walls.

Steve