CattleAc

iTrader: (7)

Pull a cover and check...

G Atsma

I have a feeling they're OK. When I first bought it, the coolant reservoir had a crack, unbeknownst to me. It ran out of coolant and got hot. That resulted in a new water pump and belts, and of course a new reservoir.
My thinking is, this one time overheating would have been THEE prime opportunity for the head(s) to crack, but it has been running perfectly ever since, with clean oil at all times. I run synthetic.

csxfbird

iTrader: (5)

Thanks for all the information so far! A couple of new questions.

1) There is a pair of original 862 heads for sale locally from a 2002 5.3...omc8 mentioned to stay away from pre-2003 heads, does that only apply to 706 casting or 862 as well? Any reason not to go with pre-2003 862 non-Castech heads?

2) I've also read that 2004+ heads use different head bolts than 99-03; is it just a matter of making sure the bolts match the year the heads are off of?

G Atsma

The head bolts are related to the BLOCK. Head type does not dictate bolt length
862's should all be OK. Only Castech 706's are affected

RB04Av

^^^ This ^^^

The heads are all the same. They changed the depth of the location of the threads in the block at some point, or maybe rather a gradual slide over a period of time. Therefore the bolt choice goes with the BLOCK not the heads.

AFAIK none of the 862s have the cracking problem; nor any other Castech made product other than 706. But I'm no authority on that.

Not sure whether overheating is too much of a factor in the Castech 706 crack. My truck never overheated at all, never even came close, in all the time I've had it. Which it had I think it was 60k miles or so when I got it. I suspect it's more a matter of heat cycles... the # of times the heads go from overnight cold to fully hot. Not that overheating WON'T or CAN'T cause a crack; please, no one put THAT statement into my keyboard; only, that the particular cracking problem in question doesn't "require" it, and can readily occur without it.

The places in Cattle's photo that are labelled "oil drain wells" are also the head bolt holes. Those 3 in the center that his photo points out, are the ones I've seen fail. The 2 bolt holes at each end, I don't know.

omc8

iTrader: (7)

The reason I said to stay away from the earlier heads ..... 1999-2001 were notched which limits your selection of head gaskets unless you have them welded up and then milled, is best solution to the problem. Otherwise if want to use a MLS gasket - Fel pro makes a permatorque MLS that will work . I have heard that if you use arp bolts they have enough clamping force to do the job .So if you're sure they 2002 you should be fine as they were MLS .