EricD

iTrader: (2)

Hi and it has been a while.. I want to pick up a clean set of 799 heads off a 4.8l with VVT from a 2017 savana van. My question is are they the same as other 799 heads that did not have VVT. I imagine the VVT has no parts in the heads as it controls oil to the lifters. Will i be ok bolting these heads on a 2003 LQ4 6.0l build using pre 2004 bolts. I will be using the original valves and rockers but putting aftermarket springs and pushrods as i am changing my cam. Thank you. Eric

G Atsma

A 799 is a 799, which are identical to 243's. Best stock cathedral going. They are all the same.
You have VVT confused with AFM/DOD. VVT varies timing with the cam sprocket by using oil pressure to retard timing as speed increases. It's AFM/DOD that deactivates half the lifters to make the engine into a 4 cyl. under very light loads.

EricD

iTrader: (2)

Thanks for the info. Apart from the Ls2, a transplant in my friends 2002 camaro, i have worked alot on Gen3 with 3 swaps and my silverado so all this VVT and AFM DOD is new to me even given the fact that it has been around for a few years. I guess most people are deleting all this stuff who want to seriously modify. I use efilive sense 2008 and love it . So even if the 799 heads came off and engine with AFM DOD it would not make a difference . Thank you G Atsma. Eric

wannafbody

iTrader: (2)

Heads are the same but strings and valves vary by application.

EricD

iTrader: (2)

Just got the 799 heads yesterday. Just wondering and maybe i am just worried for nothing. In case my pics dont get uploaded i will explain. They are the same casting 799 but the stamping numbers dont match and the 799 casting number on one head is a bit larger. I am doubting they are from the same year or even same 4.8 but maybe gm did that. I dont know if the valves seals are good as the intakes are very oily but could be oil that got in. All the tops of the intake valve stems where the rocker contacts in both heads are darker then all the exhaust valves. When i took the rockers off that were already untightened one of the bosses that the long rocker plate sits on seemed to be grinded on the side over the intake . i looked very carefully with a magnifier glass and it seems like something was grinded . it lookes like a gap that was filled but not sure, could gm have debured an imperfection . I compared these 799 to a pair of 853 ls1 heads i have that are older and all the valve stems tops are of same color not at all darkened. Did these 799s get hot. I noticed that on the exhaust side of one of the heads on the inside behind the valves the whole lenght of the head it is darker, could that be just the oli but the other 799 head is not at all that dark. I do have some new seals i can use but what about the valves and the grinding. . Any help would be appreciated. I was happy to find these 799s because this stuff here in Quebec is harder to come buy than in the states but i dont want to end up worried about these when installed. I looked on summit for a complete set of stock ls valves but did not find them. I imagine SDPC has them but how much . Thank you. eric

G Atsma

It does NOT matter whether they are the same year or even if one is a 799 and the other a 243. The castings are IDENTICAL! Much ado over very little.

EricD

iTrader: (2)

I have uploaded some pics of the heads.

EricD

iTrader: (2)

Well the pics worked. Thanks guys. eric

EricD

iTrader: (2)

What do you think of the pics. Thanks G Atsma

G Atsma

Those heads look fine. Clean 'em up and run 'em!