Head Gasket Combo?

[welpro222]

Whats the recommendation for head gaskets for the 6.2?

So for i'm looking into using a Fel-Pro 6.5 9701-pt Gaskets and the ARP Studs.

I know the ARP Studs are good to go, but are the 6.5 gaskets better then the 6.2 gaskets?

 

[TCUCV]

Always use OEM parts that are designed specifically for your truck . . . $.02

 

[Asgar]

From what I could find at the time the FelPro 6.5l headgaskets were re-engineered to work better than the original 6.2l version. If the coolant hole shown a few posts below is not present I was told the 6.5l version can be used. If you have the hole, use the 6.2.

I installed the 6.2 version 3 yrs ago without any issues on my stock 6.2 M1008. I did not need to pull the engine, there was plenty of room to pull both heads.

You should be able to verify this via some web searching.

Spend the time to properly prep the block and head or the gasket may fail

 

[dstang97]

yes, 6.5 gaskets are better

 

[Asgar]

Wellpro222... I went to my parts log and did not find a reciept that had the actual felpro number on it that I used. I re-checked 'the diesel page' 6.2 engine manual and yes, the 6.5l gaskets were better engineered and compatible with newer 6.2l engines. There is still a 6.2l gasket made because early 6.2l heads had extra coolant holes. If you have this coolant hole you need the 6.2l version of the gasket. If you don't have the extra holes, you can use the better 6.5l version, which is metalized.

Since I did not find the reciept, I can't in good faith state for a fact I used the 6.5, I'm working from memory 3 years back. What it comes down to is if the extra hole was not present I used the 6.5, if it was I would have used the 6.2l.

I took a picture of the extra hole and attached it here, if you have this hole use the 6.2l version, if not, you can use the 6.2 or the 6.5 but the 6.5 will be the better gasket.


The 9701 gasket has heat cured sealant on it, don't touch it anywhere except for the edges.

 

[welpro222]

Sweet thanks for the info. Also, the coolant passage that is right above that extra hole in your picture? On my 1991 6.2 block, it is open in the back and closed in the front. On my 1983 6.2 block, is open in the front and closed in the back?

 

[Asgar]

I found the gaskets I pulled 3yrs ago (as I got the truck, stock 100 and pics are below. The old gasket clearly shows I had the coolant hole in the head I showed above (red arrows above and in this pic below) so I would have used the 6.2l gasket, not the 6.5l version. (still, the 6.5 is a better gasket, but with the hole the good folks on the 6.2l diesel page would have steered me to the 6.2l gasket) This is the first pic below. If you want to go with the 6.5 gasket, seek advice from above or at least a real 6.2l rebuilder.

On your 83 vs 91 6.2 block question, Could it be they changed in 1991 due to the 6.5 or tubo's changing the cooling needs? 6.2l rebuilders should be better sources for advice.

On the cylinder heads... GM had a problem with a core clean out hole (a hole to remove the molding core junk after casting). They had so many issues with head gasket leaks at the lower rear corner of the drivers side and the lower front corner of the passanger side because of this core hole the stopped putting it in during the 1984 prodution run. They created a specially shaped drive in freeze plug to plug this hole if you ever had earlier heads off. The GM part number is PN-14077197 for this plug and driver, not sure if it is still availible. They say it was for 82-83 6.2l heads. Does this hole line up with your 83 block hole? The hole is not on my 84 CUCV, but I sketched it in on the picture, green arrow, the pink lines are my attempt to show the valves and pre-combustion chamber.