Brief history;

Was gifted the take-out Engine/TPI/Shorty Headers from my neighbors 1991 C4. She replaced it with a crate motor due to a head gasket issue.

I decided to use it in the resto of my Rock Crawler, especially because of the TPI. Upon disassembly, it broke a head bolt and an intake manf bolt in the #8 cyl area. There was also evidence of a lot of coolant leaking down the side of the block on either side. Evidence suggests someone replaced the head gaskets before this last failure due to style used. Did not notice any sealant on the head bolt threads (likely reason for the tightly siezed head bolt).

The heads are the 113 casting and don't show any corrosion issues. What is glaring to me is the lack of aluminum around the coolant passages with these castings. As such, I TIG welded around the trouble (to me) areas and resurfaced. However after that fact, I noticed I neglected an area on both heads. When I blued and scribed the ID of the fire ring, it was evident that the fire ring was just barely being supported by the head casting and no more... ??? I called Felpro for some input and was told it was not an issue, and their #1003 gasket was a better choice for this job instead of the 7733 PT. The ID for fire ring on either is 4.125", the 1003 has a Stainless Steel fire ring.

Anyone notice head gasket issues with the #113 castings... ??? What gaskets are you using... ???

Thanks in advance !

 

Its common for them to toss them in the 7/8 cyl. Pretty sure mines starting to seep. Smell it here/there no other evidence, thats how the 89 started though. Id use the best HG you can get.

 

Not surprised it's a common issue due to the amount of aluminum GM skimped on when designing these heads. I'd expect them to crack or severely "cup" on the deck surface if overheated. I can also see why they would leak where they meet the block on the exhaust side, … NOT enough aluminum to stay stable when heated. Losing the #7/8 gasket seal makes sense since the rear of each bank is the hottest running due to coolant flow. Too bad, … they seem to be a nice head other than the thin casting approach. I'm using what I got, knowing the short-comings going in. I'm going to use the FelPro #1003 with the SS fire ring armor.

Any other input appreciated !

 

PS;

The exhaust seats seem to be VERY hard in these particular heads. Cutter deflection was an issue after installing new guides custom made from CHE blanks.